Yes, you actually can have these different channels linked under a single Google account.
1) Set up a Google Plus Page for your YouTube account via https://www.youtube.com/account (requires g+ account) Note: This may overwrite avatar and channel title, and may change your YouTube display name to whatever you set your Page Title to be.
2) Your personal g+ account will be the owner of this Google plus page.
3) Repeat for other accounts, setting up their own google plus pages.
4) You can add your main personal g+ account (if you have one for each unique gmail) as a "manager" of these other pages, giving a single login access to the pages (and therefore all the associated YouTube accounts) via the drop down "switch acocunts" on YouTube (top right drop down)
5) After a page is old enough (2 weeks?) you can change owners so your main g+ page owns the page. Not necessary but helps consolidate + lets you abandon other personal g+ accounts.
Let me know if you're able to follow that. There are benefits to doing this with only a single channel. You won't be able to see "combined" analytics but you can switch accounts much, much easier.