Honestly, I have no idea what I'd do. My balloon twisting partner (who is moving away, so it'll just be me) doesn't know as many designs as me, but she has a decent repertoire and is very creative with the Sharpies. So, I've never worked with someone who is a good deal worse than me. I'd most likely explode from frustration.
On a side note:
I dislike going places where there's a balloon twister who clearly doesn't know what they are doing. There's a guy in his twenties around here who is at literally every event I've seen. Bee festival? Check. Renaissance fair? Check. Farmer's market? Check, check, check. As far as I have seen (by his menu board and by watching him, haha, I'm a stalker) he knows less than ten designs. He doesn't use 160s, bee bodies or 350s/60s... or even Qualatex balloons. And his prices are astronomical. I'm wondering how he gets hired!
He doesn't seem to do any birthday parties though- I think I'm the default for that.
But seriously, he just doesn't know enough to be a professional twister- not claiming that I am one, but I know y'all who are, and you would likely laugh at him. Sorry to rant, as I so often do.