What is the record for career hits by a pair/trio of teammates?

Ty Cobb and Tris Speaker were teammates on the 1928 Philadelphia Athletics, combining for 7,703 career hits. They were also teammates with Eddie Collins, for a combined total of 11,018 career hits. That should be the record, using the method you've used here.

caspian88 certainly has the trio answer -- the 1928 Athletics are the only team to have three members of the 3000 Hit Club after they had reached 3k.

Teams with two members are sparse:

1927 Athletics (Cobb & Speaker, but the '28 A's obviously has a higher hits total).

1995 Indians (Winfield & Murray).

2001 Padres (Gwynn & Henderson, but it really lasted only one game -- Rickey got #3000 on the last day of the season, which was Gwynn's final game).

I suppose there might be teams with one player well into the 3000s and a teammate somewhere in the 2500-2999 range, but I do not have that research handy. Given the 1928 A's had Cobb well past 4000, that team probably retains the title.

I think caspian88 has it with the A's. FWIW, if you go back a year to 1927, they also had Zack Wheat and his 2884 hits. 13,902 for four players. Course they also had Jimmie Foxx, Al Simmons, and Mickey Cochrane. Have Lefty Grove as your starting pitcher, and you could just about have an all-HOF lineup.

You can't count Jeter and Suzuki because the latter had the majority of his hits while he was with Seattle, and Jeter was washed up by the time Suzuki came to the Bronx.