In this scenario the rogue traders entourage has approached the garrison commander and has rolled fellowship to convince them to offer assistance against their enemies. At this point they had several skill based options for immediate results and an important additional roll they needed to make.
Any of the basic interaction skills using fellowship: command, barter, charm or deceive, could have worked, most of these would have required an opposed test be made by the commander but as the GM had decided the commander was neutral it is to easy salvage the mistake and state they pass with no degrees either way. Of these skills I would have chosen barter described on page.77 as it can assist with an acquisition roll see page. 271. More on that in a moment.
Also note if the character who rolled the dice didn't have the appropriate skill, their effective Fellowship would have been halved, potentially reducing the number of degrees of success. They may have also had an advanced interaction skill that they would have preferred to use.
At this point the player has convinced the garrison commander to offer their assistance, we could stop here, they'll probably send their forces to assist and the degrees of success could potentially translate to the commander sucking up or trying to impress the Rogue trader and friends, GM's discretion, degrees of success or failure do not necessarily effect every roll, but in this case their is actually a way those successes can translate into an improved permanent result...
The acquisition roll.
The acquisition roll determines whether or not the Rogue trader and their serfs can set up the required supply chains, accommodation, training regimens and other long term requirements to operate the company permanently essentially making the company a resource the rogue trader can call upon at will.
The test is a simple d100 check against the party's profit factor. Having rolled well on the interaction skill you can gain a modifier to the acquisition see page. 273. This essentially boosts the players profit factor. For all other modifiers I refer you to table 9-35 on page. 272. I would estimate a company of soldiers, of standard quality with basic gear actually nets the party a +10 to their effective profit factor. As lasguns are so plentiful.
Remember the power of aquisition can not bend reality, the commander can only give what he has, but the party can purchase better gear or put the men through expensive training. They roll for what they want the final state of the resource to be given an appropriate amount of time and paperwork. Not what they're getting immediately.
The aquisition rules put the results of a failed roll in the GM's hands, maybe the party can roll again but for a lower standard company of recruits, or a company armed only with unreliable flintlock rifles. Failed rolls can't be reattempted for a better or equal result.
Once all this is done congratulations the players are now the owners of a company of the emperors finest cannon fodder, to command at their whim.
The GM could also in the future have the player roll an upkeep test to maintain the company whenever something would affect its operation.
The complete Rogue Trader acquisition rules are between pages 271 and 276.
Optional modifiers distinguishing between type and quality of soldier as well as what to do in this scenario when recruiting mercenaries can be found in tables 4-2 4-4 and 4-5 pages 118 through 128 in the rules of war chapter in the Battlefleet Koronus supplement.