Honestly, niether. It's definitely not an eye-popping, garunteed to win type team. But it is also not a garbage, 12th place squad.
What worries me mose is your bigts. Duncan is still a beast when given minutes and healthy, but he is always a cause for concern for those reasons. Biyombo is still rare and unproven and can't be counted on for anything besides blocks. I like his upside and it will be great if he can score around 10 pts and get nice rebs, but as of right now you can't really count on that.