Quantity vs. Quality
Russia has always outgunned NATO in terms of raw numbers. Russia's military strategy for decades, possibly centuries, has been to throw lots of warm bodies at any problem. This is why RU has more than 10,000 tanks, allegedly. Frankly, having this many tanks is borderline silly. Almost nobody can afford to operate this many tanks simultaneously, and keeping a large reserve is basically an admission that your tanks have low survivability. Not really an inspiring message to send to your tankers. Just for perspective, consider that RU built more than 80,000 T-54s in its history. By comparison, the US has built barely more than 10k M1 Abrams.
Active vs. Reserve
The reality is that RU invaded with ~2000 tanks. As has widely been reported, this was likely almost their entire fleet of operating vehicles, due to widespread corruption in the RU army. So two critical questions that must be asked are:
- How many reserves can be made operational?
- What is the quality of the reserve vehicles?
Unfortunately, we don't have any reliable sources to tell us how many stored T-72s are unusable because of raided engines, barrels, and optics. But it is not hard to find intercepted calls where RU tankers complain they were sent into battle with defective tanks with multiple problems that rendered them nearly unusable in battle. If these are the ones being actively pushed into the front line, you can imagine that there are thousands more sitting in warehouses and fields which simply cannot drive onto the battlefield, or fire any rounds at the enemy.
What we do know is that RU is deploying T-62s to the front lines. We know that because UA has captured them and documented the fact. This would be comparable to the US being so desperate it started deploying M60s to a front line instead of M1A2s. So when we say: "Russia has 10,000 tanks", it is quite obvious that this does not mean "RU has 10,000 T-90" or "10,000 T-80" or even "10k T-72". It is pretty obvious by now that every operable RU T-90, T-80 and T-72 is already fighting somewhere in Ukraine. Whatever reserves are left are older and less capable.
That is not to say that T-62s and T-64s are harmless and no threat to UA. But merely to emphasize the fact that the RU military explicitly values quantity over quality. NATO, on the other hand, values quality over quantity. This is why RU started the war with more tanks than all of NATO combined.
Survivability
RU designed its tanks for massed action, and prioritized offense over defense. This is why the T-72 has an autoloader which sits on top of a carousel of rounds, leading to the famous "turret toss" when one gets hit by a penetrating round. The designers knew full well that this was a risk, but it was deemed an acceptable price to pay so that the tank could fire quickly in a fast-paced offensive push. The M1 Abrams, on the other hand, stores rounds in a compartment at the back of the turret, isolated from the crew compartment by a firewall, and featuring blow-out doors so that if the turret is penetrated, the blast explodes away from the crew, rather than obliterating them.
One way to describe these differences are that NATO prioritizes the survivability of its tank crews, while RU prioritizes the offensive capability of its armor.
Actual Combat
Unfortunately, we do not have any big tank battles involving the Challenger 2 and RU tanks. The closest we have is the Battle of Medina Ridge, during Desert Storm. Here, the US 1st Armored Division, with almost 350 M1 Abrams, faced off against the Iraqi 2nd Al Medina Armored Division, with 270 tanks (mostly T-72), operated by the Republican Guard, and considered to be some of the most competent forces in the Iraqi army.
The end result was that 186 Iraqi tanks were destroyed compared to 4 Abrams. Now, this isn't a fair comparison, because the US had a numerical advantage of about 4:3 in tanks, as well as air support (AH-64 gunships and A-10 tank busters), which destroyed 38 of the Iraqi tanks. That still leaves 148 kills for the Abrams. If the tanks were perfectly matched, the 1st AD should have gotten 4/3rds the kills of the 2nd AD, just based on raw numbers. So the Iraqis should have gotten at least 111 kills. Using these adjusted figures, we see that the Abrams still got a nearly 18:1 kill ratio. On top of that, the Iraqis got the element of surprise by positioning their tanks below a ridge line, where they could not be targeted from a long distance by Abrams crews (and where the Abrams is most deadly). They had to clear the ridge line and being descending to target the T-72s, while the Iraqis could start shooting the moment they crested the ridge.
Conclusion
There's no guarantee that Challenger 2 will enjoy an 18:1 kill ratio over RU T-72 in UA. But if it did, then sending just 14 of them would be comparable to sending Ukraine more than 250 T-72s. And that's no joke. However, there is some chance that UA tank crews could see big numbers, due to the fact that many experienced RU tank crews are dead or captured, and many tankers now in UA are conscripts with barely enough training to drive the tank, let alone engage in combined-arms tactics. The biggest benefit of survivability is that one crew fighting in 10 engagements is going to gain far more experience than 10 crews each surviving just 1 engagement. Which means, the longer the war goes on, the better the high-survivability tank crews get. It doesn't even matter if the tank itself survives or is repairable. Ensuring that the crew can step out and live to fight another day carries a tremendous amount of battlefield value all by itself.
While the Challenger 2 is not the Abrams, they share many advanced technologies and design decisions. We have plenty of reason to believe it will perform more like an Abrams than a T-72. And if it is joined by the Leopard, and eventually the Abrams, then RU T-72s are likely to become an endangered species within the borders of Ukraine.
