If the gang knew Ignis' crush and saw how clumsy the man is with his seduction game I think Gladio would be the best wingman and Prompto the worst. Gladio would make sure she teams up with Ignis for reasons, he'd tell stories about how dorky Ignis is so she doesn't see him as stiff and he'd make sure they always end up going shopping together. Meanwhile Prompto would be like "hah, no wonder Ignis is mad about you" after she says something remotely cool to him.
That would be so adorable of Prom, even though directly afterwards in the awkward and slightly terrified silence that follows he would realize what he said and be like
Then he’d babble to you to forgive him and to not say a word to Ignis because he’d flip out about it (and now Prom is worried about getting his ass beat by Ignis and/or Gladio), but while he’s yammering nervously you’re going back into the recesses of your brain and replaying all of Ignis’s little quirks around you
… and you realize that you’ve felt the same way about him, too.
Prompto is looking up at you in horror when you stand up and pat him on the shoulder, telling him thanks with a warm smile before walking off
And it’s only until later that evening when Prom gets a text from Ignis with the words, “thank you”, that Prom lets out the breath he’s been holding all day.
Because you see, Prom wasn’t really the worst wingman; he was just the sun that shone light on the situation at just the right time. ☺️