Can you go wrong taking an Orion on the table?
We start off at range with an AC/10 and an LRM-15 pack. I like LRM 15/20 packs on my mechs which means if you roll average its a decent amount of damage, while if you roll legendary your opponent gets soaked for the while spread. 5/10 packs have a different role in the game. Combined with the AC 10 this has punch on the way in as a way to lay down some covering fire if part of a lance, or if you are sending off the Orion to take on a mech alone the AC and LRM can start stripping armor and setting up for crits.
Get close and we switch to the medium lasers- always reliable. Can also shoot the AC/10 without having to worry about minimum ranges. But soon, like this, we start dealing with hear issues. I try to park my Orion somewhere so it doesn't have to run/walk so I'm not building heat from that. Of course I'm missing out on the movement modifiers from my opponent' shooting, but hopefully I can grab some cover. Bonus as there is no shooting modifier working against me with my shooting since I'm standing still. I'll switch to the SRM-4 once we are real close since the heat vs. damage means I want to hit with that, trying to cut down on movement modifiers.
With the Orion's armor, it can hold its own for a bit, and while not the most gunny heavy mech, it has a response to the other mechs it will engage. Besides, if it is good enough for Kerensky, It's good enough for me.