My problem with /holiday eng is not that the weapons in it are overpowered in certain situations. I don't like /holiday eng because it's easy to get those weapons without any work whenever they're most advantageous without actually having to strategize. I don't see the point in adding to something that shouldn't be there to begin with.
I think 3 is enough. If you add more, then the nades pickup will make no sense anymore
You say this like having the ability to magically summon grenades makes sense, which it doesn't. You can blow up vehicles with one hit with grenades, in the right circumstances. If you can get them from a command, then it's very easy to almost always have them and use them successfully in those conditions, even if your gameplay otherwise completely sucks.