Any Battletech game should be set no later than the Fourth Succession War (3028-3030). The silliness with the Clans was the beginning of Battletech's long decline.
That's fucking nuts. For a number of reasons.
1. Plot. Kerensky gathers the galaxy's military and takes off, swearing to return when needed. 6 million people, tens of thousands of ships, mechs, tanks and other materiel. And they just... stay away because you're butthurt the plot finally advanced?
2. Time. Clans invasion happened in ~1990. The boxset at the time was this ugly piece of weeaboo shit. Fast forward 6 years and you arrive at the 4th edition boxset.
4TH EDITION BOX SET.
That's fucking right. Instead of some cunt robotech bullshit, you've got a fucking skeleton faced mech with its arm blown off and smoking, firing off a giant laser into some shitbag. I can smell the John Phillips Sousa from here. Open the box up, what do you get? A 2 color image of some macross mech in crosshairs? FUCK NO. Zues getting its shoulder blown off from a fucking oompa loompa mech while infantry storm across a smoldering battlefield. FUCK YEAH.
3. Technology. Pre-Clan invasion there were two weapons that could headcap a mech, 1 of which was a magical artifact that about 2 people in the fucking universe had. Everything was slow, plodding, and took fucking forever to play a game. Clans show up : Boom. Let's all kill each other faster so I can finish a game in a few hours and maybe do someting for the rest of the day, rather than penciling in the Charger's 120th circle of armor because you brought a fucking Banshee to the fight which can't put out but a few points of damage a turn anyway.
4. Fuck you. Fun shit is fun. Go be old somewhere else.