There is an alternate use case that Earth Dragon did not touch on in his review. There have been a few ally spam decks I've played where I regularly have all ally slots filled and multiple chump blockers on their last legs. In these situations, Toe to Toe has no downside. I get 5 damage, and open a slot for my next/better ally to hit the field.
Others have all-ready outlined its main function being healing allies so instead I'll note a few of my favorite targets. On Giant Man the 2 healing can equate to 8 damage. Captain Marvel (Signature Ally) gets 4 Thwart or Damage plus 2 card-draw. Wasp gets 6 damage and Goldballs gets 8. When used on Storm (with an applicable side scheme target) this can effectively remove 8 threat.
If you have a mystic identity this card is worth considering. It is has an effective cost of two cards (Played Card + Discard Card) for the benefit of drawing two cards. Because the discard is after the draw phase, it will allow you to cycle and keep cards you want in your hand.
Another interesting addition is that this an "Action" card. This means you could play it in either alter-ego or ego
Others have touched on the value this card provides as free chip damage (in some cases buffing damage to dealt to multiple targets). I also think it’s fairly valuable in a minion killing deck with cards like Into the Fray and No Quarter. In addition to providing extra damage, any excess damage gets converted into either threat removal or card draw both of which are more generally more valuable than damage itself.
TLDR: Turns HP/Recovery value into card draw over course of game. A must include depending on player count and hero.
Generally anything relying on Minions or Side Schemes is going to become better with increased player count, especially minions since their HP doesn’t scale. At 1 player this card is a maybe include for minion heavy scenarios. At two players it’s a must include for minion heavy scenarios (on specific heroes). At 3-4 it becomes viable across most scenarios based on minion frequency. This card is going to feel particularly good on Heroes like Hulk, She-Hulk, or Wolverine. Really anyone witha high health pool and/or recovery that likes to basic attack. She-Hulk really enjoys flipping down frequently and this gives her another reason. Venom also has an above average recovery stat and Project Rebirth to encourage flipping down. His Pistols and Run and Gun encourage basic attacking.