Frontal attack the Soviet method not 3:1 but 6:1 at least. Only massive fire superiority will succeed without communications. Funny the Germans attempted something similar in 1940. North of the country at a place called Kornwerderzand. They didn't get further than a probing attack, only place in Western Europe where the Wehrmacht was stopped. No way they could flank there, the Dutch Navy supported the defenders in the bunkers which were very strong defensive positions.