As a matter of fact, FASA has always meant TT Battletech to be a tabletop Point Value game of lance vs lance TACTICAL 'Mech combat, given that any featured 'Mech had a Battle Value (B.V.) specifically designed for lance vs lance combat only, so much that when they decided to abide with the fan base request of larger scale engagements they released a quite different and very simplified rule set called "Alpha Strike" purposefully built in order to allow for up to company strength battle engagement.
From this logical stand point, HBS' BATTLETECH is an outstanding video-game adaptation of the TT version.
Finally, this is a TACTICAL 'Mech combat game, not a STRATEGICAL 'Mech combat game, isn't it?
My point also applies to TT BT, but there the mitigating factor in TT's favour being that the limitation is not hard-coded to unit count but points value of one stripe or another, where you get what you pay for and the other guy is on even terms. In HBS BT, the limitation is either flat unit-count or tonnage on some missions, and the OpFor uses different rules, which all conflates towards maximising concentration of power (which means an inevitable bias towards assaults).
That said, the equivilent of more than one platoon of vehicles does not make it a strategic engagement. I'll also point out BT TT was more thorough than most wargames, actually, when it came to adding combined arms, artillery, supply, air support etc. The very early concept might have been just four units per side, but long before I came to BT in the mid 90s, it had expanded to well beyond that scope.
Two or three lances in this version of BT would not make it a strategic game; what it would mostly make it is just LONGER, cumbersomely so, given it is TB.
(BT slightly shot itself hard in the foot from a gameplay perspective by making a lance four mechs in this sole regard; as stuff like X-Com and most CRPGs (and even table top RGs) show, six is usually about the optimum number. (COMSTAR apparently have it right...!) (From a real-world military perspective, there's a good reason why tank plattons are 3-4 tanks, of course, so in every regard but the meta-game small unit play perspective count four is right.)
Eight would be too many, given the multipliers of force required to compensate for the AI dificiencies compared to a human player, but five or six would probably have allowed some more room for mechs that make a better 5th member of the 5-6 man band (the bards of the group, as t'were...)
As I said, I am not saying that HBS made a wrong choice to make it just four units; but that choice comes with its own set of drawbacks, same as the alternatives do (in this case, it means that some units are simply not best used in ths sort of environment).
The problem with Alpha Strike (and its ancestors) is (at least as far as I can see) that what fundementally makes BT BT is the nuts and bolts[1]. Take that away, and Alpha Strike doesn't have anything to offer that other abstracted TT wargames rules don't already do significantly better (unlike a computer game version like MechCommander 2 where you can get away with it and have to). If I'm going to play BT with a dozen mechs, I'm going to play BT, not Alpha Strike.
[1]Let me be clear; I'm far less interested in the politics of the houses than I am in the technical readouts and the histories of the mech designs; the politics is just something to hang the technical readouts on, pretty much as far as I'm concerned.