While it's too soon to assess the impact they'll have on formats like Pioneer or even Commander, I can tell you that they add intriguing dimensions to draft and sealed gameplay
Closing Words PRB02 brings new strong cards to OPTCG, boosting the performance of multiple old archetypes that have been out of the meta for a while now
Alternatively, you can play a little more politically and strike up a deal, offering those cards to someone instead of forcing the issue
If its on the board early, it can tank damage while you build up your main damage dealer
What makes the Guardian good is the ability to get bigger things out faster and to splash for big threats
Of course, heavy use of auras can easily be the build for any of these commanders, and theres some overlap on the lists, but I look toward some broader build options here