I can see Scavenger not replenishing those (as getting a free tac/lethal after every kill would be stupid)..... but I think the ammo crate should....
I made a "Boom Boom" class for fun (Under-barrel Grenade Launcher + China Lake [or w/e it is] with Danger Close), and it's lame that even the ammo crate won't refill them any. Of course Scavenger would be OP on that class, so i'm glad it doesn't.
Scavenger: Fine as is; maybe let it refill 1 lethal IF the person you killed had the same one you do Ammo Crate: Refill ammo; and grants 1 lethal/tac. Launchers are given 1 as well. You have to wait 15 seconds before using the crate again.
B.S. in Computer Science; Minor in Game Design & Programming - Rochester Institute of Technology (RIT)