Desired teams per server when replica factor is 2

We typically use the replica factor as 3 when we calculate the survival chance at simultaneous failures.
When the replica factor decreases from 3 to 2, the number of all possible teams decreases, which in turn decreases the survival chance.

- [ ] What should the `DESIRED_TEAMS_PER_SERVER` be when replica factor changes to 2?
- [x] Does the team collection work without error when the knob `DESIRED_TEAMS_PER_SERVER` is changed to value not 5 or 1. Right now, it is only tested for value 5 and 1.

Start by reviewing the team collection logic and the existing tests for DESIRED_TEAMS_PER_SERVER values 5 and 1. Determine the expected value when the replica factor is 2, verify that team collection works with another knob value, and add coverage for the agreed behavior.

Written by the indexing model from the issue text.