Not to argue with anyone, but I think it's easier to sound like some other band after the fact. They definitely were not the innovators that The Beatles were, but since the Beatles already existed and were still a commodity, other bands certainly could tap into their sound and mimic it.
I remember when John Bonham died, people said that there will never be another like him...and they were right...but there sure are a lot of people that have studied his sound, play the same drums tuned the same way and can transcribe/play what Bonham played.
This happens all the time in the jazz world....Someone like, say, Jaco Pastorius shows up out of nowhere, pulls all the fret wire off a beat up P bass and turns everyone on their ears....A few years later, everyone has fretless basses and sounds like Jaco and can play every Jaco solo ever played....but, again, it's all AFTER the real innovation has taken place. Mimicry is different from creativity.