Guderian, Bastico, Horton, and Konev on the obvious choices of super tank, medium tank, 2× cruiser and rocket arty respectively.
Pavlov on the mechanised inf.
Leeb to spawn in a 3× submarine.
Bastico to enter the sea and sail for the Yucatan Peninsula of Mexico.
The rest to attack Florida.
Horton, Leeb and ships to block the stretch of sea from Cuba to Mexico and clear any ships from there.
Afterwards, use Konev or Guderian to shell Havana and the other to sail towards it.
Jump from Cuba to Mexico after beating enemy gens.
Travel behind your ships.
Now, move your ships to finish Kuznetsov.