*Note: This whole post is just me theorizing on what seems plausible from this standpoint. It's not definitively saying that any of this will happen.
Saskatchewan: TSN's Dave Naylor wrote this week that the three leading candidates for the Roughriders' job are former Eskimos' coach Richie Hall, former Winnipeg coach (and current Saskatchewan offensive coordinator) Doug Berry and Hamilton defensive coordinator Greg Marshall (this one, not that one). Let's take a look at each scenario in order.
Richie Hall: Hall's hiring might not have a huge domino effect, as he isn't currently employed elsewhere. It's odd to think that he could be fired from the West's worst team and hired as the head coach of its reigning division champions in the same offseason, but he's very well-regarded in Saskatchewan from his time as the Riders' defensive coordinator, and the mess in Edmonton was far from entirely his fault. In fact, once Eric Tillman came abroad as general manager and gave him some pieces to work with, Hall's record was quite impressive. He could do quite well in Riderville if given strong personnel support from Ken Miller and Brendan Taman, and he does appear to be the leading candidate at the moment.
If Hall is brought on board, it would be interesting to see what he decided to do with the current assistants. Berry might not want to serve under the man who beat him out for the head-coaching job, and defensive coordinator Gary Etcheverry and special teams coordinator Jim Daley both took their share of criticism this year. Both of their units performed quite well in the playoffs, but Hall might also want to bring his own guys in. If he does that and hires people away from other CFL teams, that could create openings for Daley, Etcheverry, Berry or others.
Doug Berry: Berry's hiring also wouldn't necessarily have a huge domino effect, but it would definitely mean that the Riders would need a new offensive coordinator. Taman knows Berry very well from their time in Winnipeg and Saskatchewan, and Berry did great things with the Riders' offence this year.
It's also quite possible that the Riders could bring Hall in as the defensive coordinator under Berry; he might take that job, as he's expressed a desire to get back into coaching, and he's not getting a head coaching job anywhere other than Saskatchewan this offseason. If he and Berry can work together, that might be a best-of-both-worlds approach; it could see Etcheverry at least going elsewhere, though.
For the offensive coordinator slot, one name that comes to mind is former Tiger-Cats' offensive coordinator Mike Gibson, who left this week to try and find a more westerly job. Well-respected offensive line guru Steve Buratto, also late of the Tiger-Cats, might come with Gibson; he apparently wants to be closer to Idaho, and Saskatchewan certainly qualifies there. The Tiger-Cats are going to be looking for new guys to fill those slots regardless, and it's going to be interesting to see who they come up with.
Greg Marshall: Marshall is a little further off the radar, but he's been a very successful defensive coordinator in this league and he does apparently want to try and land a head coaching job. He also has a history with Taman from his time in Winnipeg. If the Riders do go with him, that means Hamilton's going to need even more new assistants; it also might see some turnover in the Saskatchewan coaching ranks, with Marshall either trying to bring in his own guys or the current assistants departing on their own terms. His hiring would probably cause more league-wide ripples than either Berry or Hall.
Edmonton: The Eskimos' coaching search is tougher to narrow down, as Eric Tillman appears to be talking to just about everyone at the moment. Still, a few candidates stand out. Let's break down three of them.
Kavis Reed: Reed, the current defensive coordinator and assistant head coach in Winnipeg, has been a hotly-rumoured candidate for the Edmonton job for weeks. He has a history with Tillman from his time in Saskatchewan, and he's worked in offensive, defensive and special teams positions, which adds to his appeal. If Edmonton winds up going with him, it will be interesting to see how they fill out the rest of their staff. Tillman's been speaking with Stampeders' assistants Chris Jones, Dave Dickenson and Rick Campbell presumably about the head coaching job, but it might not be too much of a long shot to envision any of those guys perhaps joining the Eskimos, especially if the pay's right. The ripples might also spread quite a ways in Winnipeg; with Reed gone, they might try and lure Marshall back from Hamilton or find another defensive guru from a different CFL team.
Doug Berry: If the Riders make their move first and go with Hall, it might not be too far-fetched to see Berry wind up leading Edmonton. Berry has a proven track record as a CFL head coach and is an offensive-minded guy, a type Tillman has opted for many times in the past (Jim Barker in Toronto, Joe Paopao in Ottawa, Kent Austin and Ken Miller in Saskatchewan). He might be a good fit for that franchise. Potential ripples there would depend on who Berry would want running things; I could see him perhaps bringing some of the Saskatchewan coaches along if Hall doesn't seem to want them, or they might make a bid for some of Calgary's assistants. Dickenson in particular could be an attractive target. Any of those moves could have substantial effects around the league.
Dave Dickenson: Dickenson (pictured at right chatting with Stampeders' head coach John Hufnagel last year) is a bit of a long shot, as he doesn't have a ton of coaching experience and was more of a de facto offensive coordinator than a de jure one this season in Calgary. Still, he largely ran an offensive show that put up 626 points, 105 more than any CFL team and 129 more than the closest West Division team (Saskatchewan).
Calgary's offensive talent was impressive, sure, but much of that credit has to go to Dickenson's schemes; he found ways to take advantages of Henry Burris' strengths while minimizing his weaknesses, developed the best ground game in the country with a Joffrey Reynolds-Jon Cornish platoon and drew up routes that used the full potential of his receiving corps' diverse skill sets. I'd imagine that he'll be a head coach in this league before too long; the question is just if anyone's willing to take that gamble on him yet. To me, Dickenson is a much stronger candidate in Edmonton than Saskatchewan; the Riders' management team is a bit more conservative and appears to be focusing more on people who have served with them in the past, while Tillman has shown willingness to gamble time and time again, especially on promising offensive minds (see Austin, Kent).
If Dickenson winds up being the choice in Edmonton, that could set off a very interesting chain reaction. Tillman might try to even out Dickenson's inexperience with veterans at offensive or defensive coordinator (or both), and a combination of any or all of Gibson/Burrato/Marshall would certainly fit that description. Berry could be interested in the OC job if Hall wins out in Saskatchewan, although he might not want to work under an inexperienced head coach like Dickenson. Dickenson might also try to bring over some of the coaches he worked with in Calgary, perhaps including Jones and Campbell, and that could open up vacancies there for the Hamilton guys or whoever winds up on the outside in Saskatchewan. A Dickenson hire might be a bit off-the-board, but it can't be ruled out, and it would really kick the coaching carousel into high gear. Regardless of how these situations play out, though, it looks like we'll be in for a fair bit of coaching movement this offseason.