If you read the initial material, Data is drastically different. There is no explicit mention of being unemotional, just that he tends to speak more formally. He’s supposed to be more like the Ilia probe than Spock.

Worf didn’t exist at first, so Geordi the teacher with bionic vision would be the most “other” character. If they’d seen any of the early press material for Phase II, Spock’s replacement there was a very junior officer.