Volk began training to pursue MMA at like 22-23, he had some Greco Roman experience in Australia before that which means very little. Topuria on the other hand began wrestling at 8 years old and training out of MMA and BJJ gyms around 14-15, had his pro debut once he turned 18.
It was a point I raised about Islam too, Volk began training for MMA around 22-23, Islam began in Tae Kwon Do and Sanda at like 8 and 10, then did wrestling for a couple years, shortly after that he began doing Sambo with Khabib and Abdulmanap but moved away, came back around 15 and dedicated dedicated himself full-time to the pursuit of Sambo and MMA, had Sambo and amateur MMA tournaments left and right before debuting pro at 18 as well. I also think it shows in Volks style, he's super athletic, intelligent and conditioned but he actually doesn't do THAT MUCH well, his striking arsenal is quite limited both in strikes and combinations he uses and ranges of which he's effective. Beyond that his grappling has always been pretty meat and potatoes offensively, it makes sense you know? It takes so long to develop things and bake them into your game. Aldo was similar, began BJJ in his teens and began MMA pursuit at 17, had been fighting pro since 17.
Volks amazing and did amazingly well with his career but it was mostly leftovers he beat to gain his fame. I kept saying Evloev and Ilia would be his legacy fights, the ones that showed he really transcended such a shallow division and 145 generation.