[Tim Kauffman]

...or could it work instead by saying that GEVs do not have to stop when entering or leaving Swamp? All other rules for Swamp still apply.

...or instead of Marsh hexsides and all that "fiddly" stuff, we could simply have a full hex size Marsh only which would allow GEVs to not have to stop before entering or leaving. This would only be one new Terrain Token, a lighter green and less dense Swamp looking Terrain hex.

We could rephrase the official rule something to the affect that Swamp and Marsh are neither considered Water or Land. Thus GEVs moving from or into a Water hex that is either from or into a Swamp or Marsh hex does not affect there movement. All other rules still apply.

It's late as I write this, so maybe this is too far out there. Apologies if so.