Managers, here I am sharing my experience of Alliance. I am sure this will help you as well before joining any Alliance.
Weekly Alliance Series could be one of the important source of revenue for your team. You must pick an alliance that will give you good returns by winning you matches.
1. It's does not make much difference if you choose Open or Close Alliance. What actually matters is the members. Only difference is that your request to be a member of Closed Alliance Group could remain pending for indefinite period. So, consider good Alliance members and then go for any Alliance.
2. Join an Alliance which has 5 or 8 members at present.
3. Look for the activeness of the Alliance member by going through their last online dates. You surely do not want to be a part of inactive alliance.
4. Give a look at the profile of your alliance members and try that they should belong to similar or higher level.