Eh, the big problem with the 'hopper is that its firepower is far better at sandblasting than hole punching, and its not equipped to crit seek. At range, it's outgunned (LRM-5 and LL vs. LRM-15 and AC-10), and even in close it only pulls even with the Orion for firepower (LL + 4 ML's vs. AC-10 + 2 ML's + SRM-4). Barring any extremely lucky dice rolls, the 'hopper's going to have to spend about 10 - 12 turns chewing through armor to get to internals, while the Orion with its better hole-punching ability is going to start going internal around round 8 - 9.
Basically, the Grasshopper has two means of winning. It gets into a knifefight and manages to stay in the Orion's six long enough to breach the back armor, or it gets really lucky early on and a lucky 2 causes one or two engine hits. If either of those things happens, the Orion loses. Otherwise, I see the Orion coming out on top of an extremely long, bloody battle of armor attrition.