I'm leaving this info here in case someone in the future is interested in the same. It was quite tough to dig around until finding it ...

Apparently the orange standard Ford fan switch is 97-102º C or even 98º-103º in some versions, so the fans will come on when you hit 102/103º and turn off when it's down to 97/98º again. This roughly relates to 3/4 gauge range when they kick in, and around 1/2 when they shut down.

You can find a 95º-100º (Usually brown) switch and a 88º-95º (Usually green) one if you prefer, but you have to search for a CVH one, not specifically Fiesta Turbo, or you will only get hotter ones. The 88-95 is probably only of interest if you have an 82º thermostat and want the car to run colder.

Ideal CVH running temp is about 90-95º, so the standard switch is kicking in only when it's really much hotter than that, and barely brings it down to the maximum ideal temperature. It is therefore a bit of an "emergency" setup, meant more to prevent the engine from cooking and not so much for keeping it at ideal running temp.