Illegal since, while white capturing 2 black pawns on files c-f supports 3 of the white promotions and 2 of the black promotions, the remaining white pawn capture on f and h files cannot support remaining white and black promotion, nor leave black pawn on g6.
R3b1rb/1b2b1NN/q2P2pb/p2N2QQ/2n3p1/P3BNKB/1r3nP1/2R1R2k b - - 0 1
Single Check wx 1 wp 3 wpr 4 wpx 1 maxuwp 1 minopp 2 bx 2 bp 3 bpr 3 bpx 2 maxubp 1 minopp 2
Illegal since, while white capturing 2 black pawns on files c-f supports 3 of the white promotions and 2 of the black promotions, the remaining white pawn capture on f and h files cannot support remaining white and black promotion, nor leave black pawn on g6.