I would definitely bring one. Dutch Wonderland is a pretty good size amusement park and having a stroller goes a long way towards avoiding the "crankies" when they get tired.
Plus it'll probably be fairly warm at this time of year and the shade from a stroller might be a nice break if it's a really sunny day. They have a great water play area for the kids, so don't forget a change of clothes, towels and swimsuits!
Having a stroller just makes it easier for everyone and cuts down on any stress. And DW is stroller friendly so you won't have any problems as far as getting around.