A few quick points:
1. Ask if artillery is off-board; on-board artillery is generally a pain; IF you have to use on-board artillery, keep it out of LOS and as far as you can from the main battle (provided you don't exceed 8 mapsheets, which increases flight time). Don't forget to take into account flight time, so plan ahead.
2. Protect your artillery! The Behemoth is an excellent asset for this; its MP profile matches the LT's, and it discourages light units from getting to close.
3. Indirect LRM Fire: This is a force uniquely suited for indirect fire, with Hunters, Sturmfeurs, and even the Behemoth. Use it! Keep your scouts/spotters as far away from the action as you can, but with LOS to the battlefield, keep your Hunters out of LOS, and if possible fire every turn; your spotters don't need to fight, just relay coordinates for the LRMs and the Long Tom(s).
4. Avoid exposing the Hunters to direct enemy fire, so they can continue the indirect fire fight. Notice that Hunters pair very well with Vedettes, sharing MP profiles and having complimentary armaments. Use this synergy by pairing them; the Vedette takes care of the direct threat, while the Hunter supports; a lance of 2 each is a powerful thing.
5. I echo JadeHellbringer regarding the Schreck; the anti-infantry variant is a bad idea, particularly if there is no infantry around to use the MGs on...
6. Regarding the drones, either works; the tracked (8/12 MP) should be far from the battle: sitting still in a nice clump of trees with a good view of the battlefield when nothing is near, and moving from forest-hex to forest-hex to rack up target mods while bad guys are close enough to shoot it. The hover is an evil 25/38 MP critter that should be moving fast enough to never get hit; its
cruising speed is 25, which equals a +6 modifier to hit; if possible, end movement
behind a woods hex that does not break LOS to the enemy. Ideally, you should have one dedicated scout for every dedicated indirect fire unit (including artillery); the Packrat will do, though it is overbuilt for the role. Plan your drone/scout moves at least one turn ahead.
7. Packrats should be loaded with infernos; smoke is great for building a screen breaking LOS with your Long Tom nest. Remember, the scout is not there to kill the enemy, it is there to tell your artillery and indirect fire units whom and how they should kill.
8. Infantry. I find it odd that you have Goblins without infantry, specially in such an MG-heavy environment. Ask if you can get one free infantry squad per Goblin; they don't have to be fancy; if the GM balks, tell him you'll "settle" for plain-vanilla rifle infantry of his choice. The key is that the infantry will NOT be engaging the enemy units directly, but will be well-emplaced in heavy woods hexes or buildings away from the action, but with a good LOS, serving as additional spotters. The Goblin is an excellent tank, but without infantry, it's missing its potential.
9. Special munitions. The Behemoth has two tons of ammo for its LRMs; if allowed, one of these should be Thunder LRMs (FASCAM, better known as "mine-layers"; Tac Ops pp. 372-3), in order to lay minefields along obvious approaches, so that the approaching enemy units either risk the minefield, or take a different (more difficult) path... into pre-designated artillery hexes, where the LT can rain down 20-point lovin' on their head.
Don't forget that the LT can also fire FASCAM (TacOps pp. 357), and Smoke rounds! (TacOps pp. 356). The LT carrier has 20 rounds in its hull, plus 25 in each ammo trailer (don't forget the
corrected sheets!, so you can have a couple of tons of FASCAM and at least one ton of Smoke... for a rainy day.
Deployable mines like FASCAM are best used to divert enemy units into your killing fields; if they choose to wade into them, it's just gravy.
Oh, and about the Behemoth's measly LRM-5 fields? The beauty of those is that opponents tend to think that they are too inconsequential, then walk into them, taking damage in one of two locations (RL, LL), or risking motive damage on vehicles; either way, a 4-hex spread of 5-point mines is often better than a 20-point minefield in a single hex.
10. Stop listing the LT trailers as separate vehicles. It might be your GM's idea of "correct", but all three units (well... six: 1 gun, 3 ammo, 2 support... in the old version, just one of each in the new) form only one combat unit. O0
11. You list the types of units you have access to, but not the numbers you plan to build. They seem like a good selection around which to build a conventional force. The MG Schrek and Pack Rat just make it more challenging.