It's fun to draw Iaroslav genuinely freaking out, since that's so rare. Slava, fyi, is the standard nickname for "Iaroslav."
Colonel Chekhov is an old friend of his -- you'll be seeing more of him. They met at age nineteen, roughly, and were friends ever since. (After Chekhov broke Iaroslav's nose in self-defense.) They fought together at the Sino-Soviet War (to see a picture of Iaroslav at that age, click here ) and in the Afghan War
Accurate math is accurate. Well done. :)
Yeah, I justify Iaroslav's design (vs his age) based on the fact that the guy I base Iaroslav's body type, athleticism and fighting skills on is in his fifties, and I know a man who's in his 60s (born the same year as Iaroslav, albeit on the other side of the world) who looks about forty-five, aside from his grey hair.
Speaking of grey hair, Chekhov's hair is pale grey, not white-blond. His family greys young, and, well, he's hung around Iaroslav for years. That's enough to make anyone's hair go grey. :P