The Transport (to move materials), Hauler (to move materials/med socket), and the Hound (upgraded medium socket) all unlock at the same time. Let's compare these for transport:
48 items: Transport, default. Moves 12 at speed 4. Let's say this is 12 x 4 = 48 trips by default.
16 items: Hauler, default. (which says it has "expanded storage" in the description only hold 4 items) Moves 4 at speed 4.
52 items: Hauler, medium storage. Moves 13 at speed 4.
12 items: Hound, default. Moves 4 at speed 3.
51 items: Hound, medium + small storage. Moves 17 at speed 3.
They are all virtually identical (48-52) for maximum transport rate. The transport is the most cost-efficient by far as it doesn't require modules to operate. However, we have two "primary transportation" bots at the same level with under a 10% (48*1.1>52) difference in function. Both are equally effective running errands in the base (where things only carry one stack by default) at speed 4. So how do we make them interesting and different choices?
Make the transport hold 6 items only and cost a little less. It'll make an ideal 'around the base' bot. Description something like:
"A highly efficient engine is used to transport small amounts of cargo quickly. The simple design avoid modules so more orders can be filled by having more transports."
Expand the Hauler's base cargo capacity to 9 or 12. (Bonus points if you have them visible on the left, rear, and right sides of the bot.) This will make it match the description of expanded cargo and allow it to seriously out-transport route the others at this level. It retains it's unique place as a speed 4 medium module frame.
Leave the Hound where it is. It is "A well-rounded bot adaptable to any need with use of both a small and medium module slot.
Ideal game design allows for multiple, significantly different solutions to the same problem. With the proposed changes above, one can use multple transports or a single hauler. For hazardous routes, the hauler can mount a medium turret and really shine, while transports would replace dashbots/scouts around the base.
Speaking of different solutions, let's talk small towers and combat.
All three small towers (robot, virus, blight) have the same range of 5. It's a bit small both given the pathing and how high-tech these appear to be. I'd recommend adding 2 range to every ranged weapon and 1 range to most melee bugs. Keep the trilobyte and ravager at 1, and gigakaiju...I'm not sure but he should outrange or equal the small turrets. The increased range would make micro in battle far easier and give programming a bit more leeway.
Make the virus turret shorter range (i.e 6 instead of proposed 7) and deal more damage, perhaps it could use green spitballs.
Make the blight turret longer range (i.e. 8 instead of the proposed 7) and deal less damage per hit, but fire faster. It could be a continuous beam even.
Add a scaled down version of the human missile launcher for medium sockets. A rocket turret that "loads" rockets into a special slot (like blight gas) and requires them to fire would be cool. Provide a 15-ish range and a small amount of splash damage to soften bug waves.
I don't know, story-wise, where you plan things to go from here. I'm just extrapolating some things based on your existing work.
