Flying into Bangkok and was wondering what the better route to do is: I plan on doing Thailand, Laos, Vietnam and Cambodia

I am unsure if I should go from:

option 1 : Bangkok to thai islands, then northern thailand, Laos, vietnam, Cambodia, bangkok (fly home out of bangkok)

option 2: Bangkok, northern thailand, Laos, vietnam, Cambodia, thai islands, (fly home out of bangkok)

Thank you for this advice.