and what are the developers going to do if the other player just happen to be not around when matched?
u are going to be jammed there till the other player noticed he has being matched? or that player just take his own time and u are going to have to wait for his next move? complains from players that other players jammed them up and thus their arena orbs get wasted?
Oh. What I am suggesting initially is not random matchmaking. No orbs needed for it. It will only be practice mode, which is available now between guild members and your friend list. There should be 2 layers of confirmation to make sure both players are ready for battle. If the dev team can develop that initially, then perhaps later on they can already build a more complex tournament style battle, where stakes will be high depending on your bracket.
For random matchmaking, it will be the same as any multiplayer game, you will just have to enter an arena waiting room and you will be pitted against enemies within your rank range. There should be a time limit for every move you make (say 10 seconds), if you fail to make a move within 10 seconds, AI will take over your move for that turn. Or then can also employ chess rules where both players will be allotted a certain amount of time. You can also lose if your time will run out.