Eh... I feel like by making the alters come back with massive stats and boost her enough to win you really negate the realization she just had of “Oh no, just relying on stats is not enough to win.” I really think she should’ve been forced to retreat in some manner.
I also think it’s a bit of a shame the way the author has the manga laid out currently there is no real “loss” for kumo to suffer. This would be a good moment narratively for her hubris to cause the death of a loved one, or the loss of a limb, or important item, etc. leading to growth but the series is basically laid out in such a way there’s nothing to lose but maybe the alters which seemingly can only be split by Kumo’s own choice.