When it comes right down to it, an LCT's 'Mech forces are outgunned and outmatched by a typical Clan Cluster. Its vehicle forces can either keep up and be similarly undergunned or underarmored, or they can get there long after the 'Mechs are smoking ruins...
"Ultimate Death Battle: LCT versus Cluster" favors the Cluster every day of every week. The Spheroids don't need more firepower or more numbers, they need a compelling reason for the Clan side to give up the range advantage, or they get nowhere.
I say this as a (usually) Clan player, but no, just no. Even on featureless terrain with no objectives to defend.
The average Spheroid 4/6 mech still advances faster than the average Clan 5/8 mech can back up. The cluster may be able to eke out a few turns of ER large laser, ATM ER, and 5-class or smaller AC fire at 23+ hexes while the LCT cannot effectively respond. But under 23 hexes, the LCT's ER PPCs, Gauss cannons, and LRMs have the same range as the Clans' versions of those weapons. The Clans cannot avoid return fire for even a minute, forget indefinitely.
(And actually, that's not even true because the LCT has a company of artillery that far outranges anything the cluster brings to the table barring a few Arrow IV units, assuming the cluster even has them.)
On top of that, half of the LCT's 144-240 vehicles are fast cavalry units. So we're talking 72-120 hovertanks and such moving 8/12+ sweeping in from the flanks. Even a cluster composed of nothing by super-fast Fire Moths can't back up fast enough to outrun that kind of flanking force.
Even worse for the cluster, the LCT has up to a regiment of VTOL-transportable BA. Those BA battalions are just going to be flown right over and dropped into the rear of the cluster to cut off its retreat. At that point, the cluster will have nowhere to run.
It's game over within a couple minutes for the cluster. The LCT has so many hundreds of units, so many of which are highly mobile vehicles or have access to highly mobile transports, that the cluster will be surrounded and cut down in short order despite the modestly superior range and speed of its Clantech omnimechs compared to Spheroid battlemechs.
To have a decent shot at victory, a frontline Star Colonel with half a brain will augment his cluster with two or three secondline clusters when facing a force with the numbers and speedy combat vehicles of an LCT. Otherwise, it's practically a Trial of Annihilation.
Without an objective to fight over, the Clans win hands down 9 times out of 10. This is, empirically, the reason they won victory after victory in the opening stages of the Invasion.
No, the Clans didn't face LCTs during Operation Revival. (LCTs didn't exist back then.) Heck, the Clans didn't even face that many RCTs. If you read the Wolf and Falcon sourcebooks or the scenario packs from that time, most engagements were under a regiment in size, not terribly different from Clan trials.
It was only when trying to take national or regional capitals (Rasalhague, Tamar, Luthien) -- or the proxy battle for Terra on Tukayyid -- that the Clans engaged in multi-regiment warfare like what fighting an LCT would be like. That kind of warfare was rare for the Clans in the Homeworlds, and not surprisingly, their record is much more mixed in those bigger engagements.
Hope this helps.