Making FPS animations in Blender and importing them to UE4

Hello, I have a question about animation in UE4 games. I’m fairly new here, so excuse me if this has already been answered before.
From what I’ve seen, people usually animate by making two armatures: one for weapon, one for hands, and then using a socket to attach weapon to arms in the engine. This works just fine for me, but I wonder if I can have just one armature for both weapon and hands and animate them together. I’ve tried it and it seemed a lot easier, so I need to know what problems this can cause me in a long run, especially if I plan on making multiple weapons. And in case both methods are wrong, what is the correct/most common way of doing animation in games? Thanks!