Back to the OP: Into the Maw, being the sample mission, is centered only on the player characters. As you can tell from the other posts here, your players are not unique. They have power, and want to use it.
My players like to fit in one guncutter, so they take 15 extra troops.
I've used both DW horde and RT mass combat rules, and they both work, and they both keep the PCs in the spotlight. The "detailed method" of the RT mass combat rules works better than the simple method for me, as it allows the players to get more into the battle. Remember all groups go at initiative zero, and if they hit each other, they tear each other up fairly fast.
Using RT mass combat rules, a group w/o another group to fight will attack as individuals. This is where I sometimes skip dice rolls. Say the group has an adjusted 40% chance to hit an individual. I just rule that 40% of the group (rounded up or down however I'm feeling at the moment) hits, and they all roll 5s for d10 damage rolls.
Of course, one way to discourage mass quantities of troops is to make the PCs roll for each trooper when they target an individual. 
DW hordes have rules for attacking individuals, which can be quite harsh on RT PCs.
While giant scope is fun, as are mass battles, you do want to keep the spotlight on the player characters.
If the players insist on gigantic battles, then try out the simple RT mass combat rules, where a battle of thousands that takes place over days can be handled by a handful of dice rolls.
If the player forces land in 22 shuttles, you can just handwave the action around the other 21 shuttles, and concentrate on what is going on around where the players have landed. Perhaps the other shuttles are pinned down, and only if the players brake out and free them will they be able to assemble their army.
And it's not all combat. This is about profit. Trade negotiations, forging peace treaties, and other social role playing challenges are all about the PCs.
And remember, whenever players delegate, they won't get the best possible result. If you want something done right, do it yourself. If they send in 1,000 household troops while they play regicide in their starship: they lose troops at a higher rate, unreported looting occurs, and if the loot is really hot, the troops may just "vanish" with the treasure.
Oh, and all those troops? And all those ratings? Some are mutants. Some are cultists. Some are in the pay of rival rogue traders. Some are spies of the Inquisition. Some are terrified about being in the Expanse in the first place.
Leaders who lead from the front should have higher morale among the crew and more fun.
And fun is what it is all about.