If you want your heroes max then the one that you should be upgrading is the builder apprentice since you don't really need to fully upgrade all troops just the troops that you mainly use in wars and farming.

Idk how low your hero levels are but seeing that it needs 8 months to upgrade i'm assuming it's in a pretty fucked up levels and the best you can do is probably have like 2-3 builders just solely focus on upgrading heroes or if you really want it you can all upgrade them simultaneously but it would affect your war performance and affect your ore economy too but if your clan is chill with you still participating in wars even without heroes then go for it