Team OVR Calculation

Recently swapped in 91 Bellingham (the free one from a few weeks ago, base 90 card with one rank) for my 92 Vieira (base 88 with 4 ranks), and my team OVR went up.

I figured team OVR was simply based on the total of each players’ OVR, but evidently higher base cards must be somehow weighted differently, since swapping in a lower OVR player can raise team OVR.

Anyone have any information about this? Is there a formula for how it works?