I cant really talk about rohan, cuz i dont like this fraction, so i dont play it
But i am really against ur first suggestion, cuz as they other guys said: mordors EG is already balanced. The only reason why their EG is possible this way is cuz of the free orcs. If they would cost ressources, even if its just 50 with pit 1, the orc spam would be impossible. Mordor need to spam orc all the time in EG to deal with other troops, and this spam would be impossilble if they werent free. Mordor need its money for other stuff^^
Also, Sauron wouldnt pay for his orcs. They are just dirty slaves for him who fight if they r told to, so I thing it is also better relating to the books/films if orcs are for free.
greetings, urukking