Those two bands can't be compared.
You would be better of comparing Ratt to Dokken
Or Black Sabbath to Blue Oyster Cult
Or Heart to Pat Benatar
Led Zeppelin really cannot be compared to any other bands. Nor can the Rolling Stones, Jimi Hendrix or Van Halen.
Yes, music and your preferences are subjective, but let's stick to reality here.
Some of these bands are/were at a level that could not be reached. Rush was not one of them. Led Zeppelin was.
Now, if you wanted to compare guitarists you might compare Jimmy Page to the guitarist from Ten Years after.
Randy Rhoades to Yngwie Malmsteen? Not so much, maybe Yngwie to Jason Becker.
Jeff Beck to Stevie Ray Vaughn... maybe.
How about Iron Maiden to the Scorpions?
See a pattern here?