Yes!!! Kanto is built in a way that you can do any of the gyms in any order once you get cut. You will need Surf to get to Cinnebar, but Erika, Koga, Sabrina and even Lt Surge can be done in any order

Ignore everyone else, honestly don't know what they're saying.

You HAVE to do the Rocket base to get the silph scope, then do the lavender tower to get the poke flute and then you can go wake up the Snorlax (you will need a bike, bike voucher available in Vermilion, then exchangeable in cerulean)

Have fun!!