Women's Six Nations: Who can rival Grand Slam winners England?

How can teams challenge Grand Slam winners England? England cruised to victory over France in Bordeaux to secure their third consecutive Women's Six Nations Grand Slam and sixth title in a row. John Mitchell's side scored 270 points and conceded just 41 in one of the most dominant Six Nations campaigns in recent years. With England seemingly getting better as they build towards a home World Cup next year, is the lack of competitive matches a problem for the championship?