Two holdings in one Alliance ?

Just wanted to ask whether the following setting is "legal" in terms of Airlinesim Rules&Reg.

Airline A1 and A2 are seperate holdings of player "A". Though they have no interlining agreement both of them are members of the same alliance. They have interlining agreements with these members as well. So for instance A1 is interlined with B1 C1 D1 and A2 is interlined with B1 C1 and E1. There are mutltiple airlines within the alliance that practice this (so B1, B2 etc.)

Of course it is. Otherwise I would be so criminal. If it would be forbidden than you would have to decide which holding of yours has to cooperate with a certain holding/airline. And that would be sh**. :D

As long as an alliance has no advantages, this is allowed.