I'm going to say too lax is superior. Because "lax" is not synonymous with "trolling" any more than "strict" is synonymous with imperial Japanese military camps. The fact that both options are prefixed with "too", I think it's fair to assume that we aren't comparing a reasonably strict regiment with the Bush Pirates, because a reasonable regiment would not imply that it falls under the criteria of "too strict". So I think it's safe to assume that both choices are going to be uncomfortable and a bad fit.
In my experience, which may not reflect that of everyone else's, regiments that are too strict are simple no fun. If I wanted a perfect re-enactment of exactly how a real regiment performed, I wouldn't be working with WASD. Even then, I know sure as hell that historical regiments weren't made of ice (at least, not the ones I'm familiar with). I'm a stupid American looking to kill time that should have been spent on homework.
Regiments that are too lax are an earful. But they're easier to keep in check during a linebattle. Teamwounding at spawn is a fairly simple way to get removed quickly from the event. At the utmost extreme, they can troll the event until it is wasted. But it's one event gone. The residues? Minimal, for while people may be smouldering at the fact that the regiment messed up the event, but they will certainly be gone by the next time around. If they aren't, it's either an error of the administration or organized trolling (which is a completely different category)
The strict regiments? They're more likely to cause some tension at the event. I've been to more than one and watched certain regiments antagonize other people for not taking the event seriously. I've listened to leaders yell at their regiment for trying to talk to the community. That is hardly an environment in which to play a game. As I said, I don't care much for joining the military.
So there's my peasant opinion, not at all proofread. Take it for what you will.