I want to try out for BYU rugby but im worried about one thing...?

hey guys! i am a college level rugby union player. up at college, i only play for my local city club team in idaho but we play different university and club teams. i am 18 years old, i am 5 feet 7 inches, 160 pounds, i play hook (and sometimes wing) i have lots of muscle, i am decently fast (but not quite the fastest guy on my team) great endurance, excellent tackler, and i have a year of rugby experience. i want to take rugby to the next level in about 2-3 years by trying out for the BYU rugby team but there's one thing that really worries me: i know that i have the skills for rugby but i am very afraid of BYU rugby coaches cutting me for just being short. I know for sure to keep on improving speed but in addition to that, should i also bulk up like a bodybuilder for more weight (since i like tackling better than running the ball)? Basically, how (in any way) can i eliminate my height disadvantage? *remember that i LOVE to tackle and i would prefer to play as a forward* thanks so much guys!