time capsule for multiple macs

There is no "best" configuration. Each Mac backs up to the Time Capsule separately and automatically once you have set up Time Machine on each Mac.

Time Machine will automatically keep the backups of each Mac separate from the others, so each Mac will only be able to "see" the backups that have been made from that particular Mac.

The practical limit for the number of Macs that back up to one Time Capsule is probably 4 or 5, although I have had 6 backing up in the past with no issues.. If you have more than 6 Macs to back up, then you probably need two Time Capsules.....with 3 Macs backing up to one and 3 Macs backing to the other.

If you have not yet purchased a Time Capsule, and you plan to have multiple Macs backing up.....buy as large a hard drive as possible on the Time Capsule. Currently, that would be 3 TB.