The challenge for me is that the Orion is functionally identical to the Marauder: same speed and weight. So how to distinguish a Marauder build from an Orion build, at least in terms of game stats? Obviously, the fluff is a little different -- the Orion is purely a FWL Kali Yama 'Mech, while the Marauder is from all over, but that's fluff. The silhouette is also different: the MAD is a chicken-walker, while the ON1 is roughly humanoid. But again, that's a fluff difference.
The major game-play distinction comes from their quirks, and the Orion is -- bizarrely -- an anti-Aircraft 'Mech that is also rugged and easy to maintain. That's a... weird combination. The AA means that flak weapons are ideal, but the rugged/easy-to-maintain encourages an all energy build that doesn't use ammo and thus doesn't tie a 'Mech to a supply depot (where it could also get ready maintenance). And none of the canon variants really take advantage of these quirks in a significant way.
I've been playing with a bunch of different builds and none of them really satisfy me. I think I'll probably try either a heavy-weight Rifleman load-out that really takes advantage of the variant Flak ammunition, or a Black Knight variant laser-boat build. The Perseus is a nice Omni concept on the design that retains two of the quirks, but has extremely limited crit slots, so can't really lean into the laser-boat builds.
The difference--as almost always--lies in the weapons mix. You can build a 75-tonner moving at 4/6 that looks (and feels) like a Marauder, or you can build one that looks (and feels) like an Orion. Try to stay true to the spirit of the 'Mech and its 3025 variants and you can't go far wrong. For example, the Orion should have (not always, but most of the time) a mix of long-and-short range missiles, short-range energy weapons, and a ballistic weapon. Whereas the Marauder (and most of its listed variants) almost never mounts missiles, being either all energy or a ballistic-energy mix.
Gives them a totally different feel on the playing field.
Now, you can break that paradigm (for example, fitting a PPC or Large Laser for the AC) and keep
almost the same feel and spirit.
You can go completely outside the box, but that runs the risk of having a 'Mech that may be quite good on the playing field, but doesn't
feel like a Marauder or Orion in play.
Anyway, you always take a risk when changing a canon design. And it will get even worse as we go up in tonnage because so many assault-weight machines are very similar in design and capabilities. (To one degree or another, of course).
Just my thoughts.
