Seemingly relevant rules:
- pg 47: "In certain circumstances your battle groups can move voluntarily through other friendly troops, but at other times this may happen involuntarily and may cause deterioration...Interpenetrations are situations where you can choose to move through friendly troops and where there is no penalty for doing so. No interpenetrations are permitted while charging. " (Says that interpenetrations are voluntary moves, and involuntary moves burst through. One could argue that a rout move is an involuntary move and must burst through.)
- pg 48: "In various circumstances, battle groups may be forced to burst through other battle groups that they cannot normally interpenetrate. This is not voluntary and causes difficulties. (Reinforces the voluntary/involuntary criteria, but the wording of the first sentence also implies that the lack of the ability to normally interpenetrate is what makes bursting through involuntary.)
- pg 108: "If any obstructions would prevent completion of a routing battle group's move, adjust as per evade moves..." (Says rout moves are handled like evasion moves, and could thus interpenetrate, as per pg. 67: "It interpenetrates friends if allowed to do so." But that raises the question, "well, are they allowed to do so in these circumstances?")
