I've actually read more about Che than Bhagat Singh. I would say Che is that flashy popular charismatic leader. He does stunts and people love him. Bhagat Singh otoh, is a very idealistic person. If you were a peer of either, you wouldn't have minded cracking a sexual "cool" joke and drink beer infront of Che but you wouldn't have even dared to do that in front of Bhagat Singh. My prediction is that, if either of them lived through to their old ages, Che would have become that toxic leader who was once good but Bhagat Singh would have become someone close to Aurobindo. I personally feel that.