So basically a cav unit? Yes drop the tonnage limit- during the era you mention it makes sense as we had a few units who might have been available to them over 55t at that speed. You might make it one heavy cav battalion and two lighter/original battalions.
In that case I would also say stack the Clan equipment in the heavy battalion- lets you bring the weight with weapons that hit harder. Your classic 3050 Omnis would fit here because many are faster than 5/8- the Gargoyle would be your biggest bruiser, something like the G with the LB-20X and APGs. But throw in the Savage Wolf, Jade Hawk, Mad Dog III/IV, Ryoken II, Arcas, Thunder, Thanatos, Falconer, Prefect (would be interesting HOW), or anything available on the lower end merc lists IMO. The light battalions would be made up of more IS designs, common ones available on the lower end of the merc and respective house lists. The light battalions would be the horns to the heavy's head in the traditional 'bull' style of envelopment attack.
