Can anyone explain what the Rank 5 Rogue Trader Talent "Master & Commander" is supposed to do. The text reads..

"By spending a Half Action in combat to direct the efforts of his allies, none of them suffer the penalties for ganging up until his next Turn" (p103)

But the only reference I can find to "ganging up" in the book (p249) gives a bonus, not a penalty.

(The second half of the description, spend a half action to give defending armsmen a +10 bonus in defensive boarding actions, makes sense but doesn't quite justify a Rank 5 advance on its own)

I took it to mean that the bonus to be hit by the larger group is negated, but it's a generally useless talent in my opinion.

It sounds overpowered to me

This talent allows a small group of characters to block a larger amount of (melee) opponents without getting hacked to bits effectively holding a bridgehead, a very powerful talent.

The second part is the real problem, it refers to p. 215 boarding actions in ship-combat. Problem is ship-combat a) has no half-actions and b) in boarding actions the fighting power of your crewman is irrelevant (rule-wise), its the command check of the commanding officier thats important, and he needs his action to do just this. Think this talent was written before the ship-combat rules were made and got overlooked after that. It needs an erratum or at least a clarification.

Apart from the fact that ship combat indeed knows no half actions, I think the talent's effects are relatively clear in intent if not in wording: In small-scale combat, you negate the ganging-up bonus enemies receive. In boarding combat, you grant a +10 bonus on the boarding roll. Whether that works only if someone else uses his action to coordinate the boarders and you essentially assist them or if it also grants a +10 on your own roll is not quite as clear, especially since the boarding section doesn't actually say that coordinating your troops is an action.