You… you do realize, they’d function the same either way? I’m not sure what you think you’re paying for?
You can have separate Alpha accts. Logging into some of them just to start a skill training or a BP cooking. And then you log out again. If they’re Alpha, they don’t cost anything.
The only difference is that if you wanted to make several of them Omega for some period of time, you could log into all 3 of them at once. If they’re on the same acct, you can’t. For instance, you cannot have a Cyno alt on the same acct as your Cap pilot. You literally cannot light a Cyno for yourself, log out, log back in again, and then Jump to the alt. But you could if they were separate.
They would only cost you 15 PLEX more for that little bit of training time. And they would be infinitely more useful to you in the long run.