Martial Prowess and its aspect-swapped siblings coming in the Quicksilver pack are what I call conditional resource generators (CRGs), or 2nd-tier producers. Conditional because they only product resources for a specific thing, and 2nd-tier because you often want prioritize playing always-useful resource generators like Helicarrier, Quincarrier, God of Thunder, etc. in play before a CRG. Having an extra Physical resource every turn to use for playing attack events is handy for an Aspect filled with them, and there are some Aggression attacks that do something extra when at least one Physical resource is used to pay for them (Relentless Assault, Surprise Attack) or paid for completely by Physical (Drop Kick). However since most decks don't run a boatload of attack events, they aren't always going to have an attack event in hand to make use of that extra resource. That means a single copy of Martial Prowess makes it into most of my Aggression decks since it's nice to have but not so necessary that it warrants multiple copies.

Why does Spider-Woman factor into the equation? Because Justice and Protection have some neat attack events that also get better with Physical resources! With either Concussive Blow or Tackle in addition to Pheromones you could have a very nice lockdown package. Momentum Shift and Swift Retribution (Scarlet Witch pack) are both cheap, which plays into S-W's game plan of playing as many cards from different Aspects as possible each turn. Her basic THW can take care of a lot of threat in 1-2 player games so that can free her deck up to focus on the nice attacks between Aggression and Justice or Protection. And the icing on the cake is that Martial Prowess is an Aspect card itself so it boosts S-W on the turn it's played, unlike most other resource generators.

In summary, extra-punchy Spider-Woman is quite fun.

Nice concept. The card does seem like a better fit for Jessica.

As you point out, looking at deck density and operational plan are important. I would like to have a deck density of more than 1 per hand-size which is part of the Hulk problem. Too many of Hulk and She-Hulks cards are not attacks. Only 2 of Hulks 15 signature cards are attacks. The only other attack cards in his stock deck are Drop Kick and Toe-to-Toe .

The Operational Plan is also important Ms Marvel Bio-Kinetic Polymer Suit is amazing not only because of the 1-cost and high deck density of events, but also because playing an event every turn is exactly the operational plan. With solo Hulk you have too many turns where playing the Thwart card is a more time essential play.