This is an interesting scenario. Have you made the map in Megamek?
My comments on the units: a Company of LRM Carriers can do a lot of damage but I wonder how many actual hits they can score on a full company of fast Medium mechs with JJ. Once inside, the Scorpions can be taken at short range and with physical attacks and SRM infantry will survive more or less depending on the number of MGs you bring to play. If you bring Inferno SRMs it can be a very short engagement.
I see little use for mechs without JJ and also for Light mechs because of weak armor. Slower mechs will be an easy prey for the LRM carriers
So, as attacker, I would use a full company of Medium mechs with JJ. As defender, I would trade the Scorpions for a smaller number of SRM carriers and instead of Field Guns with AC2s and AC5s, I would have them with AC20s.