Enfilade (and routing in general...) [Napoleonic Battles]

[Mowgli]

The manual is not very clear on this important topic.

WHAT THE MANUAL SAYS

According to the manual p.23, an infantry unit in line formation that takes fire from the sides or rear (not from the frontal cone extending from the two hexes in front) is enfiladed. The effect of enfilating fire is increased by the scneario's enfilade fire modifier. In addition, the manual (p. 33) states that a unit suffering enfilading fire has its morale reduced by 2 for the morale check (!).

So, by reading the manual, one would think that a unit suffering casualties immediately checks to see whether it needs to conduct a morale test and, if so, becomes either disordered (on a pass) or routed (on a fail). Just like in other Tiller games. If it has been shot from the sides and has suffered enough casualties to undergo a morale test, chances for routs are highly increased.

OBSERVATION IN THE GAME

However, that's not how it seems to work in the actual game. In the game, units only rout (= take morale tests?) at the start of their own turn, not "during" the action in direct response to individual fire actions.  

QUESTION
So I wonder: 

Do units conduct only ONE SINGLE morale test per turn, which takes into account the accumulated effects from the last turn? 

Or does the game conduct morale tests per individual fire action (as in other Tiller games), but doesn't show the effects immediately. I.e. the game would remember the results and present them to us only at the start of our next turn ("this unit routs because it failed one of its (many) morale tests last turn")? 

I'm really confused. In particular, it would be interesting to know if a single pesky skirmisher unit (whose fire alone would have never triggered a morale test) can "combine" with the fire of other (non-enfilading) units to achieve a -2 morale malus the target unit.