Imagine BG character based on luck, (25% crit chance, 220% BG skill). I haven't played with such, but if i could get free 220% in SG to shoot you in the eyes with Sniper Rifle to knock you out and then finish bursting with minigun I would definetly make a sniper/bg.
I don't think you really considered everything I said. If we assume that hypothetically, in the future, it becomes harder to hit people in general based on AC, and harder to crit them, and even more so against characters who specialize in dodging or avoiding crits, generalizing won't be a bad strategy. I never said it wouldn't be good. But if you generalized, you might end up having trouble dealing with either extreme.
And the availability of guns. If it suddenly isn't viable to always have the best possible guns ,that also changes things. As it is, the way you arranged stats and perks would make a character either very mediocre at using both, or gimpy/wasting his time using the other. And it's not like a Sniper character can't keep an AR or SMG on hand to HURR burst anything that gets in his face anyway. Some of them are competitive with a Minigun, which only does 8-11 damage, even if it does have 30 rounds. A greasegun of all things does 10-20, and has a 20 round burst, besides taking 1 ap less to shoot. your assault rifles do more damage. The minigun takes 7ap, and requires 7 strength. There is not a standard Sniper gun like the Sniper Rifle that requires more than 5 str, and you need to dedicate pe to see far enough to make them useful. Clearly, you wouldn't have a very good character if you aimed to use both with the same skill, especially if you had flaky, random perks to try and do both. You would be very average. And that's not good the way we strong arm, twink build characters.
