A lot will depend on the terrain, of course. Sometimes the Martian player will have no choice but to bunch up.
Terrain has extreme importance with tactics. As the humans are defenders, they usually get to choose the terrain.
So far, the human player has learned that their advantage lies with artillery. Given the "fact" that Teddy Roosevelt believed in "build what works" I have no doubt that the industrial power of the US is churning out guns and ammunition as fast as possible. Even so, I agree that human force lists use a lot more artillery than is typical in "real" TO&E.
The lavish use of artillery doesn't bother me too much. This is a game, the object of a game, even a re-enactment, is to have fun. I personally like games with a lower figure count, and infantry is a pain to paint, so my human list is light on infantry. As a player, I usually love infantry, and I'm going to add to my doughboy count as I can afford to.
One way to deal with Human artillery is to get a drone controller close enough to swarm the big guns with drones.
Drones are not effective as "shields" but they are effective as screens. Use them to root out ambushes, use them to tie down infantry. Getting them into the fight can be a challenge, but they are not pests; they are excellent combat units.
Don't forget the use of Gas and Dust.
Remember: Humans are squishy, and Tripods are honkin' big boots.
I agree with hardlec, those drones can be dangerous, especially the melee intensive Scorpion. But, even the 'basic' drone comes with a light heat ray (short ray a problem), a reaper tentacle (equal to human grenades in assault), and has the same movement in terrain as does their human counterparts. Add to that a better defense and armor then human infantry types. Whats not to like a the same cost as human Assault/Armored infantry? A mess of those things coming at your trench line has caused many a moment of doubt in human players. Once they sweep over the trenches and beyond, the human player realizes that the tripod isn't his only concern. Killing controllers is essential to stopping trench and other terrain positions being overrun.
Eeek! right there in black & white. Dang. I'm getting fuzzy on the battles I found at Historicon and am not sure what range the Scouts were at; great point and I'll amend my stuff regarding the 'triads' to reflect that better. Ty!