Since about 1963, The Dave Clark 5 we're regarded as the Beatles rivals, but somehow stumbled to keep up with them over time. How would you have em out do, or at least stay as relevant as The Beatles or the Rolling stones
Dave Clark was a control freak over 'his' music. Unlike most Bands, he kept rights to all the DC5 music, not the Label. By 1970, the rest of the Band was tired of being treated like studio musicians, and split. The new lineup really did not work, and Clark sat on his music for the next 20 years.
So it was never in movies, commercials, K-Tel compilation albums, all that stuff that kept other '60s music in the public consciousness. Not even re-issues of original singles albums, So unless you bought old Vinyl, you couldn't get any DC5 recordings
The public at large, forgot about the DC5, even they had more '60s hits than anyone that was not the Beatles.
Then add in the Clark wasn't one for experimenting on the tech side, most of their stuff was Mono, and the few Stereo releases weren't taking advantage of the format either, like everyone else was doing after 1966
And forget about quadraphonic.
So those are some of the changes to do, and have him be not such a dick to the rest of the Band, listen to their ideas on broadening the sound, So much experimenting on making music(early synth, Mellotrons, etc) as well as upcoming styles that were mostly ignored, that didn't have to be. If anybody needed to abuse chemicals for awhile in the '60s, Clark was that man. Needed to loosen up.