Adjust growth rate based on rank or count

I'm glad I could (almost) help! The numbers are off because I didn't quite understand what you were attempting to do, and it seemed sounder to make the X% adjustment to the actual stats, rather than the average of the stats' percentages. That's what my initial effort does. The crucial part I didn't understand was the need/role for the bit with the percentages in rows 33:35. I still don't quite get it, but I don't think I need to - I'm pretty sure I can make the math work. Try the following in B30. As before, it must be array-entered with Ctrl + Shift + Enter:

=B$29+(0.09*$M$30*ABS(ABS(B$25-8)-8)/SUM(ABS(ABS($B25:$J25-8)-8)))*B$28

Fill right through J30, and the totals should adjust such that the average of the percentages in B34:J34 is adjusted according to the input in M30. Experiment with the attachment a bit to see if it holds while you tinker with the character build/settings.