Interesting that the Army is using multiple different systems. Usually, the idea is to have everything use the same system for logistics simplification.
Iron Curtain is an odd system, it appears to use unlined shaped charges to break the incoming immediately before it hits.
Iron Fist is like the Arena and Zaslon systems, basically 40mm bouncing betty rounds.
Trophy is basically a radar-guided shotgun.
If I was going to set up a tank with Active Protection Systems, it'd be a layered defense like the Navy uses on ships. Quick Kill (missiles) for longer-range interception, Iron Fist for close-range, probably some reactive armor, plus jammers, chaff, flares, decoys, the whole nine yards.