Picking an Alliance Captain after they have already picked

[topgun]

Is an Alliance Captain allowed to be selected by a higher seeded Alliance Captain if they have already selected teams for their alliance?

Example: Alliance Captain #8 selects their first choice and second choice and we are proceeding back up to Alliance Captain #1 in the selection process. Alliance Captain #8 had not previously turned down an alliance invitation. Could Alliance Captain #N select Alliance Captain #8 as their second choice alliance partner?