It's fine to be crunchy it just needs less grit gumming up the gears. I keep coming back to the cluster hits table, critical hit tables (because there are multiple), and the pointless detail of the hit location chart because they're very obvious extra layers that don't do anything but make resolving attacks take longer.
Mods, forgive me if I'm getting too close to Fan Rules territory.
It's been mentioned previously that moving on from the cluster hits table can be accomplished by making currently cluster weapons a fixed amount of damage to one location and another fixed amount to adjacent locations. Ultras are one place that this becomes cumbersome but I don't think it's a particularly unheard of option to have them roll to hit twice (especially if the second shot is at a penalty to prevent an Ultra AC from being just two ACs taped together). For everything else assigning damage adjacent works fine.
The various levels of critical hits tables and endless rolling to determine which slot you hit (seriously, it can go for a long damn time if crits have already started piling up) can be replaced with a fixed table by location; you could even replace the huge pile of mostly empty space where the current critical location table is with that. A single roll and a single result, whether that's a destroyed weapon, an ammunition explosion, an engine or gyro hit, a limb blown off, whathaveyou.
Critical hits are one of those places where there can be a ludicrous number of dice rolled in order to accomplish absolutely nothing when a hand actuator gets blown off. I mean, what are the actual results when a critical hit check happens? Most of the time, nothing. Sometimes you lose something utterly meaningless. Rarely, you lose something important like a weapon. Equally rarely, you might take some MP damage or reduced effectiveness out of an arm. Very rarely you have something truly catastrophic happen that kills the 'Mech. What we as players trick ourselves into thinking is that anything significant happens on any given crit check, but in reality the vast majority of times a crit check happens the result is nothing.
Cut out the middle-man. Structure damage to an arm? Roll 2d6. On a 2-6, nothing happens. On a 7-8, an actuator is damaged; +1 to things in that arm. On a 9, an important actuator got hit, +2 to things in that arm. On a 10, say that a weapon got hit, destroy one at random. If that weapon has ammo, make another check to see if it explodes (9+ maybe? Spitballing here). If there is no weapon but there is ammo, pick a ton at random to explode. If there is no weapon or ammo, upgrade to an 11: arm disabled, can't do anything with it but it can still take damage. On a 12, the limb is just plain gone.
And just like that, we've reduced a process that used to take potentially a dozen rolls (everyone on this board has experienced what happens on a 'Mech with seven slots occupied in an arm, you're lying if you say you haven't) and now it takes exactly one in the vast majority of results, and a whopping two at maximum. The detail lost is negligible: the sum total of things that you used to be able to have but can no longer achieve are individually striking poorly placed heatsinks and electronics equipment. That's it. Truly a staggering loss.
Location tables are more complex and are absolutely infringing on fan rules in the wrong board, but it's entirely possible to similarly streamline the process without losing the detail that makes BattleTech BattleTech.
