The US Army has been standing up heavy Brigades and converting light infantry, armor, and field artillery units to heavy ones for the last 2 years in order to prepare for near-peer threats. I watched it happen at the Division level last summer. While strapping new gear on the Challenger seems shaky at best, that Active Protection system is a lot more effective than you might think. No human attention needed, effective for guided ordnance, quick enough to react in an urban environment from someone firing from the third story of a building almost directly above you. Consider that heavy armor engagements are usually won by whoever hits first. Disrupting the first shot of an ambush makes the defender's job a piece of cake in comparison.