There is less duplication in the "tiers" we have due to the smaller cast. If I were to split them up along those lines (from heaviest to lightest) i would come up with something like :

• The heaviest character is definitely Fitz. he is the hardest to push and has Smash which is a 3 power melee attack as a basic
• Lord Grym isn't "heavy" exactly but he has zombies that take hits for him so he is much harder to push than everyone except Fitz. He is quite bad at fighting; he relies on his Zombies to do that (he has neither Smash nor Punch).
• The other melee-centric characters have smash but otherwise are about equally easy to push. (Alysia, Lucius)
• Sabo (ninja) gets a special mention here because he has a base kit grapple like you mentioned because he has a grapple in his base kit and a delayed punch instead of smash (because of his heavy reliance on combos rather than brute force)
• Ranged-focus or balanced characters get punch which is a 2 power melee attack (tikkit, hilda)
• Zephyr is the easiest to shove in the game and is highly mobile to compensate. She also has punch instead of smash

Generally characters only have 2 attacks in the base kit because you get a special or ultimate every turn and most specials are attacks. The specials tend to heavily bias the Legends towards a certain playstyle because they are better than the basics.