Alright. I have a couple of Atlases, Highlander IICs (which I use as regular Highlanders - I think they're better looking sculpts), Black Knights, Tempests, Lynxes, Wasps, Archers, Kintaros and an odd Lancelot. I also have a Bombardier, Shootist, Excalibur, Marauder, Warhammer, Mercury, Catapult and I found an odd Hussar. I've also managed to locate a couple of Rhino and Puma Tanks.
I have more, but there's no way to lay my hands on them for the time being. I haven't purchased any new minis in a long time, so if I want to create a more modern WoB force I'm going to have to buy them. (Which I'm all for!)
I'm going to create a Company based on what you have and give you a sense of how I'd play them out. Based on SLDF choices.
Assault LanceHighlander
Atlas
Shootist
Black Knight
Heavy LanceBlack Knight
Marauder
Archer
Warhammer
Cavalry LanceLynx
Kintaro
Spartan
Lynx (Kintaro) - Depending on NARC force or not
Pursuit LanceHussar
Lancelot
Spector
Mongoose
First off, depending on the scenario, you either select the Assault or Heavy lance. Assault for defensive engagements, the Heavy for offensive ones. Either way, they will comprise the center piece of your company. The Cavalry and Pursuit lances are to be used in similar fashions. Set up on either flank, they keep their move mods high, poking and prodding with long ranged weaponry, closing in for the kill on isolated or heavily damaged targets. Meanwhile, you trudge your center piece forward to the main fray. Once the enemy is in your sweet spots, you inundate them with targets, flooding them with your Cavalry lance and sweep your Pursuit lance behind their battle lines, looking for backshots or to chase down damaged foes.
Main concept - Use PPCs and Large Lasers to open holes, then crit seek with SRMs and MLs as your Cav and Pursuit close in to finish them off.
In the Cav lance, decide if you are going to be a NARC force, as more NARC pods the better to supplement your LRM support.
Additionally, and this will be expanded upon in an article dedicated to the use of lighter assets, you do not use them like in the fluff and novels. In the novels, the lights are always getting engaged first, and are scouts of the main army. While that makes sense in the real world, in the tabletop game, light and fast assets are not to be sprinted forward at the enemy, but held in reserve to provided surgicial striking at a time of need. That is why you keep the on the perimeter of the engagement or hunt down isolated targets until they are needed for the main fray.
Another thing...identify priority targets, and ensure you continue to beat on those targets until dead. Then you move on to the next target. Always better to overkill than to suffer another round of fire from said 'Mech.