Of course this will work out. There are now the exact same number of employees at each pay scale as there were before Faye was fired, assuming Hanners isn't getting a raise to go with her roaster-training. Think about it - one employee was fired. One employee was hired. There was one Ass Manager before, there is one now.
The only difference is that Dale is getting more hours, but we don't know how many. It may only be a couple extra hours per week, especially when you factor in that Cosette will be working fewer hours now that school is starting up. This is unlikely to seriously cut into CoD's profits, assuming it wasn't on the brink of failing before. And the last time Dora hired a new employee (Dale), she admitted that the shop was doing fine, she just liked the extra income from putting in more of the hours herself. So Dora may be taking a small personal paycut, but that's a reasonable tradeoff for working fewer hours - we've never had any indication that she was struggling financially.