IMO the Orion suffers from the Large CT syndrome like Kintaro. As such trying to brawl with it is suicidal, given the slower speed. So my choice is to build this as a Mid-Long range support. You are not supposed to get get up close and personal with this mech, although a pair of MLas is provided in case something gets too close. Heat management is a bit steep, but since you will not be firing all your weapons at once you should be ok. You should be spamming LRM, and then picking off guys who are poking their heads out with your other long range weaponary. The original plan was to equip this with ERPPC, but given the nerf I think I would rather use ERLLas instead (or until that gets nerfed also). note that this is a concept only, I am not getting this Mech yet, at least not until I get to see what the rest of the Orion series are like.
and if you replace BAP by TAG, drop some LRMs (its only 1 Pod) and up the engine for more DHS inside the Engine?
Well, the amount of DHS is the same in the end. So basically it boils down to BAP or more engine speed. I don't know how the extra speed would translate into battle though fo this mech, they seem to be quite sluggish in terms of performance. But then again I don't have this mech, and is going to wait on it due to "wonderful" feedback. You are right about the LRM ammo, Maybe you don't really need 3 tons of them.
Yeah the amount of DHS is the same in the end, BUT if you lose any arms, you lose Cooling. Having DHS in the Engine inside can keep your Cooling at same level, even armless. That BAP i would only use, if you have a real Missile Boat with at least two large Missile.Pods and having already plenty of Missiles, and still have free tonnage + critslots. Otherwise you do well with TAG to targetlock some ECM.Enemies above 270m. And the slightly faster Targetlock by BAP - forget that shit, it costs you too much tonnage/critslots, which the Orion really needs every single one
Based on blaggs post: Drop down to a 300 engine, that speed really isn't needed with the range you want to be at, and could be used better. Option 1 : upgrade to lrm 20, extra ton of lurm ammo : im at work, missed out 1/2 ton of armour and things are placed badly, but you get the idea option 2: pushing the heat drop the ac ammo a little, back down on the lrm ammo 2ERLL's !!!