Rotterdam is a city that can be attacked from two river hexside: the Germany can attack with 17-18 attacking factors (18 per hex halved by river), against around 13 defensive point: 2a1 at best (worst if using defensive fleet support) or +8, if defender face down, assault.ORIGINAL: Joseignacio
That is if Holland has not being taken by the GE, don't remember the situation but I believe NE gets like 2 units max (depending of the set used) which can usually get rolled by the GE armor.
And even if Rotterdam stays untaken for the rest of the turn, those CW units would be sorrounded and in hostile land with no retreat, facing Wermacht and Luftwaffe, so I think I never saw a CW player debarking there.
Not the same case as Belgium, where you can retreat to France, where french troops can cover your flanks, and where 3 corps and some aircraft can hold half of the land out of control of GE.
the only reason for Germany to DOW Holland before Belgium is Antwerp: with CW in Rotterdam is nullified as Antwerp (thank to ZOC) in out of range
as CW i make all the time. and as Germany i don't DOW Holland if CW have two transport and two land unit ready to go in Rotterdam. only in M/A, when parà arrive Rotterdam lose relevance
i think that with the new maps attacking Belgium without attacking Holland is worst (assuming minors units are the same of now)