Depending what your 5.7s are, this isn’t a big power gap.
However I am in agreement the matchmaker should force an even number of same tier/type vehicles (ie 4 6.0 CAs and 2 6.0 battleships) on each team (so it’s 2 and 1 vs 2 and 1).
Nothing is more cringe than one team having two nassau classes and all we get is a fargo and a mikuma.
Granted, the japanese heavy cruisers in general don’t struggle with punching well above their weight despite being fairly awful hulls (at least they’re not krasny kavkaz or kirov classes…)