Hartman has been unable to fill in the blanks with quality talent. Ray Deluarentis and Will Schiffrin (who are on Bunsen) are mediocre on their best day.
It may be that Butch just prefers to surround himself with yes-men as you put it. From following his YouTube channel, he definitely seems like your usual 'ideas guy' but is not really skilled as a producer. So the biggest loss of talent in my opinion is when Butch moved away from Fred Seibert and his studio to strike out on his own.