3rd Retainer by Default, please?

[Nutz]

The tens of millions of Gil I've obtained from having more than 2 retainers must not be significant then.

I'd have to agree. Most players haven't made millions (let alone tens of millions) of gil with the 2 retainers they have. Adding 2 more would do almost nothing for the average player (pertaining to income only). Very very few people constantly keep their retainers selling items or even have a constant flow of items to sell. If you're suggesting your retainer ventures have produced tens of millions of gil then I'd have to say that you're probably just very lucky, are especially good at planning to use materials and then actually using and selling products efficiently, or you wildly overestimate the amount of gil you've made from your retainers. In any case, it's not anywhere near what other players would be doing with them. I imagine a large number of players would just become starved for venture tokens.