I am getting Thermador 36" rangetop and installing in an island.
recommended blower is 1100 cfm. Thermador has either 1000 cfm or 1300 cfm.
1300cfm seems too much.
You can always turn down a larger volume blower to slower speeds but you can not turn up a lower volume blower to higher than the rated CFM.
Also if your blower is farther away with bends in the vent pipe the higher volume would be better since you lose some capacity for every foot of run and every turn.