I really like Clive Burr's playing and appreciate a lot of what he brought to the fold, but for me Maiden's lineup was complete when Nicko joined. So much of what became signature for the band on Piece of Mind. Prior to that it sounds like they are reaching, and coming close.
I'm trying to think of another band's comp. Maybe Bon Scott to Brian Johnson..
I'm fascinated by the Clive to Nicko transition and what it means. Nicko became such a vital cog in Maiden's style. I wonder had Clive not been fired, where Maiden's sound would've gone, and what effect he would've had on the music.
To me, The Number Of The Beast is still my favorite Maiden album, and it really has its own sound and style in the Maiden catalog.
The other thing, which is an epiphany that I am embarrassed to have had fairly recently but knew the entire time is that drumming matters, and drummers are not interchangeable.