I have 1 dish per 2 tortoises.
I monitor them for 30 minutes, and i do it like this.
15 minutes per tortoise....this way i know they're eating the right amount.
My tortoises rarely eat a full dish between them.
You can over feed ANY tortoise.
Which would eventually cause Pyramiding, and if not taken into control it cna ruin a tortoises shell and body.
You should only feed as much as they can eat within 20 mins.