With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: Vocal duties were shared by guests to complement each song. In later years, Woolfson sang lead on many of the group's hits, including "Time", "Eye in the Sky", and "Don't Answer Me". Even though Parsons had a preference for more proficient vocalists who had more polish and refinement, the record company exerted pressure upon Parsons to utilize Woolfson to a greater extent, while Woolfson himself agreed that he was not in the company of the singers that Parsons wanted. In addition to Woolfson, vocalists Chris Rainbow, Lenny Zakatek, John Miles, David Paton, and Colin Blunstone are regulars. Other singers, such as Arthur Brown, Steve Harley, Gary Brooker, Dave Terry a.k.a. Elmer Gantry, Vitamin Z's Geoff Barradale, and Marmalade's Dean Ford, recorded only once or twice with the Project. Parsons sang lead on one song ("The Raven") through a vocoder and backing on a few others, including "To One in Paradise". Both of those songs appeared on "Tales of Mystery and Imagination" (1976). Parsons also sings a prominent counter melody on “Time”.
text_B: Assuming that Parsons got his wish and was able to select the other regulars based on his own preferences, would you say that terms such as proficient and polished would accurately describe Chris Rainbow, Lenny Zakatek, John Miles, David Paton, and Colin Blunstone?
YES.