Was going to post this the other day and decided it was a dumb idea and didn't bother. But now I'm going to bother *shrug*
So, instead of 1.5 slot weapons, how about just keep the numbers rounded. Double the amount of available slots to 8 then redo all the current slots for weapons. So if a weapon is 2 slots currently it would then be bumped to 4 slots. This way a 3 slot weapon would be the currently proposed 1.5 slot weapon. I dunno, I just like round numbers more than decimals.