New to Micro Four Thirds: Go Olympus or Panasonic?

Hi there! I recently made a post about getting into bird photography and wildlife and asked if the G9 or the OM1 would be the better option. I've seen that the G9 is good value but a bit dated for autofocus...so I turned my attention to the G9II and OM1 but i realized the lens ecosystem is probably more important.

I want to shoot wildlife...not necessarily birds in flight - should I go with Olympus or Panasonic for their 100-400? Or is the G9II vs OM1 the real determining factor?