Just want to clarify. It's perfectly fine to take the Unit Upgrades from Hades (specifically, the Grenades upgrade) for Zombies and Apes?

It's not that it's especially powerful (there are several restrictions between the grenades and the C weapons these two units have), it's just… heh, odd mental image. Undead Suicide Bombers, and just how are the apes going to wrap their fists around those standard issue potato mashers?

. . . and just how are the apes going to wrap their fists around those standard issue potato mashers?

At least apes have fingers, zombies don't.

While thematically it may be hard to grasp… Yes they can