Atlantean Attack Squad works best when it's together with another face-up Fish, Sea Serpent, or Aqua-Type monster. Hammer Shark is good if your deck has other level 3 or lower monsters, and obtainable from the card trader. Powerful Rebirth and Arrivalrivals can also be used to catch your opponent off guard by using it on the battle phase, but it won't force your opponent into attacking the same target.
Ties of the Brethren lets you special summon 2 other monsters that are similar right away, and the other options aren't bad. One of them is Spined Gillman, which will boost your other monsters by 400, and Lost Blue Breaker can destroy a spell/trap card. You won't be able to attack right away, and it costs 2000 LP to use, which often means you can only use it once without LP recovery, but it has good OTK potential, or use them as fodder for Citadel Whale.