Possible GW archetype: Tapping matters.

Alternately "Tap an untapped creature you control: You gain 1 life."

I can see 2 ways we can make this feel organized.

1. Individual creatures have activated abilities. Auras and global abilities trigger when your creatures tap.

2. Individual creatures have triggered abilities when they tap. Auras and global abilities give you a way to tap them without attacking.

I'm not saying that every card has to fit the way we choose but I think one of them should be the "normal" way. Then again we may find that we need both parts of the combo to be on global abilities for it to come together.

I prefer method two for the norm. Obviously, we can still have a few effect creatures additionally.

Maybe with one uncommon or rare global that triggers off things untapping.