I think that the trend in recent years is to pretty much treat preseason like practice, especially for the more established teams. So holding people out for 4 weeks due to a hammy doesn't mean that its more severe than usual. Just that they actually have an opportunity to have them sit and heal during practice/preseason.
And given the noise this year, I wouldn't really mind a slower start to the year if that meant we were in full stride come January.
I think most fans and teams realize this, but you know the NFL and media will squeeze every bit of revenue from the meaningless practice games if they can.
So I'm not too worried, except for the Safety position, since it seems that was kind of ignored so far this offseason. Sort of a wait and see situation.