It is in BattleTech BattleMech Manual ::)
I think it is important to remember that up until less than a month ago confirmed omni production for the Dominion was top heavy. Executioner, Karhu, and Mad Dog III/II(are both in production???). Now we know the Viper and Firemoth are back. But that is a double edged sword because the Executioner, Viper, and Firemoth were some of the more questionable TRO3050 Omnis, a TRO known for being questionable. For better or worse Omnis are the back bone of our frontline 'Mechs. We may have some awesome experiments in BattleMechs, which is great if you are playing Tundra Galaxy, not so much Alpha.
It is all well and good to say that we can import, but up until very recently the Sea Foxes didn't do that many Omnis either. The Horses didn't, and we aren't buying Wolf or Falcon tech. The Alliance is also idiosyncratic. There are a couple of items of interest but I am not buying a 3/5 85 tonner.
Actually there aren't that many good light and medium Omnis around. You need a Storm Crow/Nova, which I know where we can get. Then you need a fast light. We have the Viper, rules out the Ice Ferret, Mongrel is sort of in between, and the less said about the Shadow Cat the better. What would be nice would be a ultra fast light with some protection. God I wanted something like the Wulfen for us, but there was too much unpublished Dominion MW:DA stuff at the time.
Fix up that hole then get some assaults happening. Doesn't help that we have so many assault BattleMech producers and everyone thinks we Kodiak everything.
I am curious who is using 3/5 Mechs lately. It is years since I played but the local tabletop discouraged assaults. The last serious attempt at a big 3/5 camping assault I can think of is the Tomahawk and that was a bit of fanservice to an old magazine reference. I had always figured after the 3/5 Gauss burnout in TRO3055/58 the designers had been avoiding it since TRO3060.
It is sort of central to the need for a 3/5 assault. If your Executioner can eat a couple of big heavies while your Mad Dogs suppress the Dire Wolf/Tomahawk, is that a problem? It is why I look at say 80 tons for a oversized heavy 'Mech. But the Executioner does everything the 80 tonner will (80/85 tons is more efficient but you don't get that big structure/armor) and you really want 5/8 movement which is another bloody Timber Wolf. So we retain that gaping enigma of a hole between 65 and 95 tons.
PS, and I proved myself wrong about big assaults hitting the firepower wall the other day. I managed to drag 80 heatsinked, cluster averaged, points at 20 hexes out of a Dire Wolf. I am pretty chuffed about that because that beats a Kraken 3's not quite sinked 72.