However, leaving the feats as a simple,
expanding bonus misses the role they play in expressing
the deep bonds of unity they represent. An adventuring
party that takes these feats might feature similar tattoos,
carry totems or charms, or adopt a symbol that adorns
their shields, cloaks, and armor. When you take these
feats, look beyond their mechanical benefits and build
your group into a true tribe bound by an oath of friendship
and united by a symbol, totem, or other mark.
If I may point to the article itself regarding tribal feats:
The feats just seen mechanically will mostly just be boring groupthink at best or at worst "telling other people how to play their character". But when used as flavor, they can not only be mechanically useful, but feel like a part of your characters' identities and fill out how they all relate to the party.
Probably to add it to the attack rolls of the summoned creature - after all, all damage rolls are basically part of the power (similar to the way the implement bonus adds to Flaming Sphere etc. as well).Any idea why all the summoning powers have the implement keyword? It's not as if you roll to cast the summoning or anything
With regard to Tribe of the Swift Jaguar and the stacking, from what I've read here, there does need to be some restriction: imagine throwing 20 or so kobolds against the PCs when all the kobolds have taken this feat.