Challenger has pretty good armour. It's pretty good at withstanding a frontal or top attack, more so than the lighter Russian kit. Like all MBTs it's more vulnerable at the sides and rear. I doubt the Russian loitering munition type drones present a significant threat. The fact that it's a bloody massive bit of kit compared with a T72 does make it harder to hide. The fact that it weighs around 50% more than a T72 is another issue when it comes to where it can go.
Main support issue will be getting ammunition in the right place at the right time. Because of the rifled barrel Challenger ammunition is unique to Challenger. The gun does offer some significant advantages in range and accuracy, which is one reason we stuck with it until the Challenger 3 "upgrade". Challenger 3 is more of a NATO compatibility change than an upgrade.