In the old days, 30% in your friends-and-family round was pretty common.
What VCs will want to make sure is that the founders are adequately incented going forward, and that the angels before them, as a group, don’t have control or blocking rights over future financings.
If you’ve sold > 50% of the company before any traditional money comes in, and/or given up any control rights … then most VCs will want to restructure things, one way or another.
But even then, they’ll just tell you. “We’ll need to change X and Y before we can invest.”