I was in the Marines, not the army and I held a Black belt before I joined. I began study when I was around 5 years old, my father was and is a rokudan black belt. I trained and studied up until my injury forced me to quit 6 years ago. I am only now getting back to enough fitness and strength to continue.
I learned unarmed combat in the Marines which has a mixture of different styles taught, I also studied Taekwondo and Tai Chi Chuan but not to Black Belt level (it was mainly because they were the only options where I was based at various times.)
I wasn't comparing myself with anyone specifically, only making the comparison that while Van Damme has a certain skill level he is still a student (much of what you see on screen is actually Ballet and Dance techniques, not Karate or Taekwondo), whereas Seagal is a Master and Teacher. Going by their relative experience alone Steven Seagal is by far the better.
Interestingly, being skilled in a martial art, even multiple ones doesn't make you "hard" or necessarily mean you are going to win a fight, being a good unarmed fighter is about far more than what discipline you may have studied.