Fable and sub agents are two different things. There are many situations for which Fable is great, but Fable doesn't have to run in a sub agent. You can use it for your main agent and that works fine.

Or are you saying my sub agents burned so many tokens because they were all using Fable, whereas my main agent could do the same job with a lesser model?

I think the commenter (who is not me) is saying to use Fable as the main agent but then use lesser models for your subagents so that you get the advantages of Fable to plan but then the subagents don’t cost as much, and may be more focused because they lack Fable’s thinking modes.