I loath to advocate the middle road, but for the moment I think that there is merit to waiting. People are still building and playing with new toys, even if they may be sub-optimal. Lists and archetypes are changing often enough that power is more important than tuning.
Many of us have played in iteration of the Vintage format where the margin is how many copies of Pyroblast you registered, wether you played Spell Pierce or Flusterstorm as your 9th piece of countermagic. I think that we are coming into the release of IKA after a period where tuning was the premium skill and moving into a place where people are building new things with new cards and those skills we were honing are less important.
I feel like we have yet to reach the point where the meta will not adapt and open up without direct action being taking. I, from a place of no particular authority, believe we can already see the seeds of this happening; BUG lists running a Reanimate to rebuy a spent Lurrus or yoink one from their opponent. People like Iamactuallylvl1 reminding us that Tinker for Citadel beats a 3/2 lifelinker in PO. An uptick in bolts and people leveraging Sprite Dragon in more classic Xerox shells. To me all of these things look like the first steps in preying upon the assumption that it's Lurrus or nothing.
Perhaps I am wrong, and in a few weeks the biggest topics of discussion will be the correct number of Baubles and Remoras to pair with your new cat friend, and if that is the case then I will defer to those who have the tenure with Vintage as a whole to address companions both efficiently and in the right spirit. My only argument is that I don't believe we are there yet and in the oldest eternal format we can afford to take the time to get it right.
All of that said, the fundamental problem of the 8th card, no matter how many restrictions you attach to it is one that I don't have an answer for. If companions become as ubiquitous and varied as walkers have perhaps we will be looking at a game that is almost unrecognizable from the one we know now.
Karakas has arrived.