I've had a look around but i can't find a decent plugin that allows me to edit for example something to change the amount of damage c4 does to bradley

any suggestions?

There are no decent way to tweak that damage. You can for example lower bradley's health or protection

https://umod.org/plugins/explosives-modifier it changes the damage on the c4,but it doesn't change the damage done on certain things.

Just c4 or rockets too?

both and grenades, beancan grenades too.