golfer: im sorry, i seem to have misquoted the noam elimelech.
the noam elimelech bring down a medresh that at the yam, the b”y were not b’achdus. he says that is the reason why the malachim said “halalu uvdai avoda zara v’halau uvdai avoda zara” and the only way the yam split says the noam elimelech, was when HAshem said “daber el B”Y v’yisau“, which the noam elimelech reads to say “tell B”Y to be one group”
so fakert, this shows that even though there were 12 tunnels, HAshem considered it (at least?) enough achdus to split the sea.