Montana is unique in it’s drawing process. But all states are….you’ll see every state has it’s own set of rules on how they draw tags, which makes it complicated when applying for several states.
You are correct that your odds of drawing the general combo tag are pretty good. Once you draw that tag then you can apply for one of the limited draw areas. If unsuccessful at drawing the limited draw area you still have the general tag and can hunt a large portion of Montana for elk with that tag. However in your case when you only want to hunt in a certain limited draw area and you don’t draw it then you’re left with a general tag that you don’t necessarily want. You have the option to return the tag, but the kicker is what you stated, they keep 20% of the cost. Like it or not that is how Montana does it.