I figure we can cope with 3 good strikers. Sturridge isn't entirely made of glass - yeah, he'll miss games, but it's not like he missed a dozen games each season for the last few years to injury. The ankle sprain that took 8 games out of him last season was probably the longest injury stretch he's suffered.
The season before that (2012/13), he lost 5 games at Chelsea due to a hamstring injury, and couldn't get back into the matchday squad after that. He lost one game to a groin strain and then one other game after joining us.
In 2011/12, he played 30 games for Chelsea. In 2010, he played 13 games for Chelsea (+ 5 unused sub appearance) and 12 games for Bolton (missed out on 2 games probably due to injury). Again, he played or was eligible for 30 games.
So, say he's playing 30 league games a season + the majority of the CL group games, that leaves about 8 games for the likes of Lambert and one other to fill in for the league games and probably the cup games as well.
4 strikers for one position (assuming that's how we'll play) seems a luxury. 3 is about right IMO, unless we go with two up front most of the time, in which case then the 4th striker makes more sense. If unfortunately one of them goes down to a long injury, then we'll work on getting a fill in during the winter transfer window, or call up a youngster. How I think it'll work anyway.