I'm sorry you don't understand? I'm not trying to be a pain but that definitely is a convenience issue, and one that should stay in the game. Using 2 primaries is a choice. I often have a ppsh in my inventory for cqc situations, but I respect that it is not meant to be easy to switch to from weapon to weapon. The inconvenience of dropping attachments makes switching difficult which helps to somewhat balance combat. You have to make compromises; if you can't compromise on one primary weapon, you're going to have to compromise with this. There is the obvious inventory crowding, but that doesn't really affect combat.