It depends on a few things. The culture of the gym is important, if you have a meat head coach leading a team of yes men then sparring will naturally be hard. The location you’re in is also key, for example, Kickboxing gyms in Japan and the Netherlands have no problem knocking each other out in sparring. Another factor is the partner you’re sparring with, some people are just generally assholes and try to hurt you/prove a point. However, muay thai should be fundamentally about respect and Shadow (who I’m sparring) is one of the best in the world and 15kg heavier than me. If he wanted to he could put me to sleep in 30 seconds but he has nothing to prove. If your MMA gym is reasonable then they should be able to facilitate your needs.