If I, say for the sake of arguement , drop a landing craft on a formation of 2 units that are already strung out with 5cm between them, units are barged by its landing and are moved to the closest point on the outside of the vehicle from where they started. Now I might be able to do this in a way that moves them out of coherency in some situations. As they are now pinned and cannot counter-charge at the end of the counter-charge phase is one removed as being out of coherency?

I believe the coherency rule only applies to standard movement. It requires the end of an assault for the player to them move his troops back into coherency. Otherwise I could abuse such a rule with some custom 'big ass' War Engines.

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As they cannot counter-charge, they are not removed as they have not failed to use their next move to get back in coherency, as they've yet to have a next move.

That's how I'd play it anyway, regardless of what a strict reading of the rules may say.

There comes a point when you should stop trying to poke holes in the rules.

Coherency is only checked during the formations activation as far as I recall. I think you can even break coherency after a counter charge but could be wrong about that!

If a formation makes a "counter charge move" then yes , formation coherency rules apply (1.12.4) but as the 2 units in the case above had been barged they wouldn't have "counter charged " so it doesn't matter.

I believe that coherency is only checked afer any move, including counter-charges etc.

Here, the units were moved by barging - but if they subsequently attempted a counter-charge at that point they would then be subject to the coherency rules

Makes sense to me.

This.

I would consider this a very cheesy way to stop someone from countercharging and would probably let them do it anyway. Were someone to do this to me in a tourney, I'd drop their sportsmanship score.

If they were barged they are in base to base so couldn't counter charge anyway? Or am I missing something here?

The rest of the formation could counter-charge, and so the formation would count as moving and those left out of coherency would theoretically be destroyed.

As Neal says, anyone actually trying this would get seriously frowned upon.

Not sure Meph. I was only trying to make the point (rather clumsily) that barging by itself does not affect coherency per se, it is the subsequent movement that causes the concerns