Not a huge fan of the clouds (nor Strain, to be honest). If it were up to me, I'd have them give a Weapons Disabled token if you overlap them. If they're going to offer such a huge defensive bonus, then they should offer a complementary debuff to offense.

I get that people want more penalties, but I just don't see how any of them would fit, thematically. Sure, it's possible to have gases that are caustic or electrically charged, but I think when most people think of gas clouds in space, they're thinking primarily of it just blocking the view.