I also, would go with the Yellow Wrasse.
A Yellow Tang really should have a tank over a hundred gallons to be happy.
The clinical analysis of whether a fish can be kept in a certain environment, to me, disregards the mental well being of the species in question.
Let us use the aforementioned Tang. Yes, with careful handling and acclimation by an expert, he could be placed in a 20 gallon fish only tank succesfully. But after speaking with my Yellow Tang, he thinks having a 180 gallon tank filled with rock and corals is wonderful. He can sleep in his hidey hole at night and feel secure, swim in and out of caves all day playing follow the leader with the Regal Tang tankmate. He also likes to play hide and seek with the Sunset wrasse in the liverock.
I just feel as hobbiests we owe it to the boys and girls we bring home to provide them with the best chance to be happy.
GL