well they didnt attach right only 1 did but the 2nd one didnt

I have no idea, maybe you just didn't press the buttons, but if you're talking about those you mentioned below, then they have a lot of seats and each one is responsible for a particular weapon.

those 2i put 2 guns on them and the 2nd gun didnt work

МПВЧ Империя Сверхтяжёлый танковый корпус ГТТ-4000 "Острог-Б" М3

МПВЧ Союз Тяжёлая башня ПТУР HGMS-200-1 A "Ультракс" M3

and alos i have a question for the onesu have for the yellow faction andb lue factioni noticeu have big tank with 2 circles on it and u place guns on it but i put guns on the yellow one the 2nd gun didnt do anything