How good is the drummer?

tl:dr; Buying a Drummer for placeholder support with gems, yay or nay?

Wall-o-text version:

So I'm faced with this situation. As you can see, I'm KL44. I recently got Mambo to 4* and realized I'm a fucking idiot for not doing that earlier (Chased quantity over quality), no other noteworthy pets. VIP going too, since that bumps the gem acquisition numbers up quite a bit.

Currently I'm running a 7-hippo, priest-druid-alchemist combo, because I haven't had any luck with getting more priests. Last spot usually has remained empty, I've also been grinding forwards in Spirit Highlands and transing units for that. Got 2 6* arts, been throwing my honor coins down that endless well for a while now.

So with the Drummer I have a question. The most obvious and subjective one of them all: Should I get it?

Support Guide seems to omit the Drummer altogether as the other universal supports get their own little text snippet. I get that his buffs are generic, but is it better than any other random elf-unit I can throw into the mix?

As an extra:

At what point do they come viable? I realize I'm barely out of the early game (or maybe not even that yet), two months into the game, so is it even reasonable to start stacking for a situation that might come about in six months to a year? I haven't found any detailed comments on when the shift to orcs is reasonable to do, except that it requires a few pets and generally the people discussing that are well over KL100.

I've recently just opened 5-16 in SH to be able to even get Boom Boom fragments, tomorrow I'll finally acquire him. One fragment a day however means "see you next year around this time for a 5* Boom Boom".

This would also be my first Drummer ever, so it's not like I'd be enjoying that 1000% buff for a stack of drummers in the shop with it.

Worth the gems, or is there something I should rather prioritize my gems towards?