LOL, if it makes you happy, I say ship it. The whole point of fandom is we do it because we enjoy it.
I think Phil/Steve has to be approached somewhat carefully because there’s a weird power imbalance there – I’m not sure who’s actually higher in the chain of command, but Coulson also has an idealized version of Steve Rogers in his head that probably doesn’t correspond super-closely with reality. So either you have to deal with that in direct terms, or you have to discuss them getting to know one another better so that we know Coulson’s not in a relationship with the comic book character in his head, and Steve’s not taking advantage of the adulation of a fan. Unless you’re into writing that kind of darkness, in which case knock yourself out, I don’t judge.
But sure, I think it’s a perfectly valid ship with some interesting aspects to it, especially now that Coulson is heading SHIELD. (Or is he? IDK, I haven’t seen the last like, half dozen episodes, I need to catch up.)
If anon wants a rec of a great treatment of this ship, I can highly recommend Ask Galatea by thingswithwings. Sweet, gentle service submission and fantasy fulfillment that just leaves you wanting more.
I think we’re all too busy chinhanding and sighing with immense satisfaction that Marvel’s finally getting onboard the ship that’s been happily sailing unimpeded by the dictates of canon since Thor 1.