When can DM unit rally in an assualt hex?

[vince hughes]

The rules say they may attack with units already in the hex, provided those units have not already activated, implying the arriving leader my activate units in the assault hex. We did decide in the affirmative for this scenario.

I keep finding bits that you may have a further question on

It is not implying that he can activate them for any type of activation. It is specific in that they can only have the option to join in combat WITH the entering units.

The other rules of course state categorically that leaders o/s the assault can not influence assault hex units at all.

I think thats all avenues