When moving police as a result of an Ops card 2 questions came up:
1. Is there an order in which the police move or if you have multiple groups of police that move can you do them in any order?
I presume it doesn't matter for reasons I'll make clear in my second response
2. Assume 2 adjacent districts (1 and 2) that have police in them and as a result of an Ops card both groups would have to move (1 into 2, and 2 into a 3rd district). If I had to move the police in district 1 into district 2, then I have to move the police in district 2 into another district, would those that moved from 1 into 2 become part of 2's group and so would then move along into the 3rd district?
No. I played so that all the police moved simultaneously so while you do them one at a time. If you have to move Cops from A into B and then B into C. You don't include the new Cops that came over from B. So in that case Group B would still leave behind a single cop and at the end of the turn that single cop would then join the mob of cops from A.
If you need a more consistent or easier solution I suggest using the priority. Whatever card is on top of the discard pile use that priority order (highest or lowest).
Of course in an edge case this could introduce a level of discard gaming where players min-max and place discards in a specific order. To this there are two solutions
1. Ensure proper discard order. While in general the drawing of Police Ops card imo doesn't matter. In my game at one point another player tried to helpfully point out that I was drawing two cards and playing the bottom card first. To me it doesn't matter because it's just a random choice either way as long as I didn't see the cards before hand. But if you have min maxers trying to exploit the home rule I'm suggesting then play the cards one at a time and then put them in the discard so there's no question which card should be on top.
2. Draw a card just to pick priority order. And then shuffle it back into the deck or just leave it out. That should make your decisions less ambiguous.