Difference is that Chinese and Russians are more likely to explode and kill the crew if anti-tank weapon penetrates tanks armor. So far we haven't seen Chinese tanks carrying any sort of side skirts to protect tanks hull from sides... important place since a simple RPG could penetrate hull and ignite the rounds in ammo carousel.
That's because no modern Chinese tanks have ever been deployed in combat. Armoured side skirts is hardly cutting edge technology now is it? And I would also do a little more research before making sweeping and incorrect statements. There are plenty of pictures of Type99s with side skirts all over the Internet. Granted those are rubber skirts, but it would take like 5 minutes to change them out for steel or composit ones.
Raising something as easily addressed as armoured side skirts just gives the impression you are looking for examples to prove a point rather than deriving your conclusions from facts and observations.
Besides, tank design is dictated by how one intends to use them, and where one intends to use them. It is always a compromise between firepower, protection and mobility. Just because one side puts massive emphasis on one of those attributed does not make that the best design solution. Tanks are ultimately meant to win wars. Having 90% of your crews survive the death of their tanks is ultimately a poor consultation prize if the price for such high crew survival meant the losse of the war.
The best protected tank with the best firepower in the world is also useless if it cannot get to where it is needed before no bridge would withstand its weight or if the ground is just too soft for such monster tanks to move around without worrying about getting bogged down and trapped.
Chinese tanks are designed for battle out in the open country, and mostly inside China, against enemy armour and as much favour mobility and firepower over protection. With how much fuel modern super heavy MBTs like the Ambrams guzzle up because of their obesity, lighter, more fuel efficient Chinese tanks can easily exploit their range and speed advantage as well as ability to cross terrain super heavies cannot traverse to flank enemy tank formations and cut them off from their fuel supply.
Your super heavy MBTs will have 100% crew survival if they run out of fuel before even making contact with the enemy and are forced to scuttle their own tanks to prevent them from falling into enemy hands.
In addition, lets not forget the WWII German lesson. There is a balance between quality and quantity that needs to be met, or else your forces are left vulnerable. The Germans had undisputedly the finest tanks of WWII, but they were still thoroughly crushed by the Soviets because their ultra-engineered Rollex tanks took too long and too much resources to produce to make up for combat losses.
Chinese tanks might not be as good as western tanks when it comes to urban combat, but that is only because urban combat is an arena where protection is far any away the most importantly factor. But as I demonstrated above, if you pick an arena where mobility and range are more important, Chinese tanks would come out on top. No tank is king of the hill in every battlefield. It is up to the designers to come up with a design they think will be most suited to the most battlefields, and the general to pick and choose where and when he fights to maximise the inherent advantages of his tanks while denying the enemy as much of their own advantages as possible.
China is starting to look at super heavies now as well, but that is only because Chinese economic and military power has now risen to a point where it no longer looks like winning would be the hardest part in most likely wars China might likely fight. Thus, now Chinese focus is gradually shifting from winning at all costs to winning in style.
Saying that, I still think the PLA will still prefer lighter, more mobile and economical tanks. They will get a good number of the new Type 99G2 monsters, but the bulk of their tank forces will still reman equipped with the lighter Type 96s or its next gen follow-ons.
If you look back, this has actually already stared to happen with the Type99 and Type96. The 99 was the heavy, premiere tank, but the 96 is what made up the bulk of the numbers.