Main Question: Do attachments cause lag and how much?
So I am making an RTS and I have tanks. I use to have 4 parts in the tanks, 1 Hull, 1 Turret, 1 BulletOrigin, 1 Selection Part. The hull is the main part. The turret is the part of the tank that is connected with a hinge that spins like a normal tank. The bullet origin was a part that was welded to the turret so the bullets could originate from there. The selection part was welded to the hull and had a decal so people could know if it was selected.
I have since realized that I could put an attachment into the turret to get the position for the bullet origin instead of welding a part. Is it less laggy to do it this way? Also I put 4 attachments into the hull and put in beam effects for replacement of the selection part. Is that less laggy or more laggy? I am trying to make these tanks as efficient as possible since I want over 100 units in a game.