woe unto me for suggesting a spec you didnt list but...
There is no such thing as "healer spots" anymore. Blizz removed that restriction in BFA sometime. BGs can be 0 healers or (in theory) 100% healers. And Holy Pally makes for a great sort of half dmg/half dps mid field brawler if you want to play that way. And thats not just a meme this xpac, they seem to actually work really well as an "aggro healer" in pugs.
If healer restrictions were what was keeping you from rolling HPal, dont let it. They arent a thing.
But, of the two, you would probably have a lot of fun on a prot pally. The divine steed knockback pvp talent is disruptive as hell, HOJ is never not fun, bubble and LOH give you some fun outs, etc. They just get lots of fun buttons to push.
Conversely, Guardian druid just kinda rumbles around in mid, spamming moonfire and thrash and letting Brambles pad your dmg meters to huge but ultimately useless numbers. oh, youre not drawing enemy fire? better cast roots that some dumbass warrior is gonna break anyway. back to bear form.