Agreed, Rhodes proof that resourcefulness is not something reliant on engineering know how.
Stark has invented a time-machine, genetically-engineered a city with an ap, and resurrected the dead. He's got a bit more than "engineering know how".
That aside, I don't think Rhodey or Pepper being "resourceful" in armor quite works dramatically compared to the genuinely unarmed street-level types. It's always going to lack a certain level of authenticity compared to, say, Punisher, or even someone like Harley Quinn.
But I suppose we'll see if I'm right or wrong soon enough. They will likely try to make Pepper seem very resourceful, and the sales will decide whether that attempt synergizes with power-armor or not.