On the foot print issue: The leadbelchers have the same foot print as approximately 16 crossbowmen, which is a mathematical advantage for the leadbelchers. But even better, the leadbelchers can deploy 2x2 so that their frontage is narrower which makes more room inside the BSB and General bubbles for other units and also reduces their vulnerability to enemy attacks in combat, and also let's them manouver better while fitting into tighter spaces. One could argue that the footprint of the state troops being naturally wider can create a kind of defensive barrier (i.e., warmachine hunters and flankers will have further to go to do their job) and while this is important, I still think the advantage here is going to go to: Leadbelchers.
Hmm, that comparison sounds actually rather close on paper. What range do LB's have? Fighting against each other, it probably depends on who gets to shoot first. 20 crossbows shooting first are likely to take out one Ogre which apparently means they'd struggle to come out on top. LB's moving and shooting will take a while to get into CC. Even then it's not so clear cut because Crossbows are more likely to have a rank, and on a unit of 20 it's entirely possible to see a standard (screw an 8 point difference, that's still not relevant).
I don't know, let's work it out:
Just because I would do it this way: Leadies deploy exactly on the line. Crossbows deploy 5 inches back from the line
Let's say leadies get first turn. They move forward 6" and fire, doing on average 3 wounds.
The crossbowmen return fire, doing on average, three wounds. Ogres take a panic check.
The leadies move 6" and shoot. They now do an average of 2 wounds.
The crossbowmen return fire, doing an average of 2.5 wounds. 50/50 chance of losing an ogre and forcing another panic test.
Let's just say that we've got three leadies left, one has a single wound remaining. They move forward 6" and shoot, now at close range. They cause an average of 4 wounds and cause a panic test on the 15 remaining crossbows!
The crossbows hold though and return fire. Also at close range now, they do 3 wounds, dropping an ogre and a half. The ogres take a panic test.
The ogres decide it's time to charge. At 11", this is a likely proposition for them.
The crossbows stand and fire, causing 2 wounds and dropping an ogre, the remaining ogre is left with 2 wounds and takes a panic test.
Combat. Since the Leadbelchers have been passing all their panic tests, I'm going to let the crossbowmen pass their fear test. Also, I'm going to give the leadie just one impact hit since I've let a couple of other fractions fall their way, they lose this one. Let's just say he wounds with his impact hit though. Now, with no models in the back rank, the crossbows attack first with 4 attacks. On average, they do 1 wound. The leadie attacks back and stomps, doing 2 wounds. The leadie, by himself wins combat by 3 (with the charge bonus) but the crossbows are steadfast!
At the bottom of turn 4, the crossbowmen take the last wound of the leadbelcher before he gets to swing.
Final Result: 4 dead leadbelchers and 8 living crossbowmen who still have 2 turns of shooting left to do. That's even with the critical math breaking in favor of the leadbelchers (i.e., getting first turn, keeping a full leadbelcher for an extra turn and passing at least three panic checks). Crazy as it seems, in this scenario, 180 points of crossbows are much better than 182 points of leadbelchers! It's even much worse still for the leadbelchers if the Empire gets first turn, because they are likely to take a panic check before doing a thing. Their diminished number of shots means that the wounds caused/sustained ratio is going to be really bad for them.
... However, this overlooks one major issue: This scenario is never actually going to happen. Leadbelchers aren't really used for straight up fights with their opposite number, they're used for taking out fast cav and light units on the flank, or maybe occupying a building to provide covering fire. In any case, the crossbows will have much higher priorities for shooting if they are facing ogres, such as mournfangs, maneaters and blocks of ogres. Furthermore, the crossbows are actually getting charged on turn 2 or 3, instead of turn 4 because while my lone leadbelchers would only walk 6" per turn, the nearby sabretusks and mournfangs are marching 16" a turn and charging with swiftstride. In light of all that, I am still much more likely to take 4 leadbelchers as an ogre player than I am to take 20 crossbows as an empire player.