either set up group requirements, move fields at 10 seconds, or use spy accounts as starters or back ups on fields that'll need it.

You have multiple options to do with spy accounts roaming your group.

1.Use the accounts to the best of your ability when it comes to war.

2.Kick members who recently joined and are below your group requirements.

3.Move at 10 seconds.

4.Spy on them if their requirements to join aren't very high.

5.Kick members who join and don't donate(Usually those are the spy accounts).

Also spy accounts usually won't be very active, won't donate, aren't very high in power for their levels, don't talk much during wars or don't talk at all.
These are all things you can do and look for to find all spy accounts in your group.