Oh lawdy lawd, I'm laughing my ass off here. Lack of knowledge, confusing two different games, reading comprehension fail AND delusions. (also, using Star instead of Lance means you're Clanner scum and thus a lesser pilot)
Now, let's begin... First of all, MW "duels" and "deathmatch" are hardly that, as they are much more about the mathematics behind the build's optimum than about actual tactics or skill. This is due to the fact that the BattleMechs move at geriatric speeds, which when combined with instant or near-instant connection when firing a weapon with 100% accuracy means there's little need for more refined skill. There's no reflexes involved in MW, at all, as everything moves in slow motion. Your claim of a Light Mech beating an Assault Mech (even a Heavy Mech) is also ludicrous and talking out of your ass, as the methods available for the poor Light are limited in number and effectiveness. Generally speaking, it's the following:
Loadout with high top speed, ECM and long-range laser(s). The problem with this is that: Top speed is hardly of any use outside of running away, as turn rates are still limited and you have absolutely zero chance of dodging anything against a player who possesses the skill of moving the cursor over a blob and pressing their alpha strike button. Circling is also unfeasible because the target can easily keep up or catch you by torso-twisting and then obliterate you. The ECM is of dubious value as well, as its effective range is not phenomenal, Beagle Active Probe largely counters it, and the effect on missile lock is laughable. You comment about a fast, light mech being able to dodge attacks only shows your own desire for popamole: "bawww, I don't want to actually have to deal with pesky things like mobility and maneuvering." If anything, the handicap faced by Light and Medium mechs shows BAD game design, as it limits the game to "I shoot at you, you shoot at me" level. In fact, a more skilled player in a Light Mech SHOULD be able to wipe his ass with noobs thinking bigger = better. There's far more elegance in a Heavy Gear jump jetting over an Assault Gear (most likely piloted and designed by a MW player), pivoting mid-air to face its back and outmaneuvering the poor sap in every turn so in the entire close combat the Assault Gear doesn't even SEE the guy kicking its ass. Or two NEXTs fighting at a velocity of 400 mph across the X-Y-Z axis with complete freedom, each trying to find a miniscule opening to exploit in the others defensive maneuvers while unloading unholy amounts of firepower to keep up the pressure.
There's actually far less cheese builds in Heavy Gear 2 and Armored Core series (usually one uber-cheese build per game, and considered extremely bad taste to use outside of unlocking stuff) compared to MW, where you have at least two cheese builds per game (usually involving either flamers, class 20 autocannons or copious amounts of Clan LRMs). It only shows your ignorance when you think all of the additional weapon types listed just add to cheese, when there are huge differences from the start already: 1) Both games also possess large number of counter-measure systems (ie, a simply ECM activation can break the guiding of a guided mortar or missile in HG2). 2) In both cases the weapons are there to allow for very peculiar builds, like purely artillery Gears (as in, shooting from behind a mountain based on teammate reports) or melee-only Cores. 3) Unlike in MW, missiles are to be dodged in Armored Core, which is why the primary element of various missiles is mixing up the dodgers task or taking better advantage of the map layout.
The art in playing HG2 and Armored Core is not that any hit can kill (in fact, in Armored Core the mecha can take quite a bit of punishment), but that any attack can be countered or dodged if you possess the reflexes and know-how (which can require a lot, the rail sniper cannon in ACfA fires at muzzle velocity in excess of 12000 m/s). It also bears mention that the loadout mechanics are far more complex and varied, as Armored Core uses a combination of leg carry limit, arm carry limit and generator limit (+ occasionally heat limit) plus involves selecting the body parts of the Core, its Fire Control System, Radar, Energy output and storage, ; Heavy Gear uses a purely mathematical Threat Level system where various aspects of your Gear are factored together into a final number that determines where you can use it (ie, a mission might have a limit of 4000 Threat Level) AND it must reiterated FACTORS TOGETHER ASPECTS OF THE GEAR (ie, targeting system quality increases the Threat Level each weapon provides, while Maneuverability increases the costs of Run Speed and SMS Speed levels).
Finally, on the subject of mechs shouldn't even exist in Armored Core universe... Well, not only can they withstand tremendously more punishment than tanks, and possess more firepower, they also fly. And then there are NEXTs...