There's also nothing wrong with a bunch of strong brick buildings and red cover. Just don't put them on the VPs, fuels or the cutoffs. The original CoH1 maps offer a pretty good example of proper garrison usage: easily flanked and never locking down access to portions of the map. (Semois pin aside, though I do personally feel that is perfectly valid.)
TBH it's really hard to design a competitive CoH2 map, for the game design issues previously mentioned. It's even harder to create a visually appealing CoH2 ma: there's not a whole lot of non-rural non-snow options in CoH2 unfortunately. It's also a challenge to create a CoH2 map that isn't a copy of another map, as there is a crushingly limited number of territory resource points with no variation.
Accomplishing all three isn't exactly easy.
I think it's possible with imagination but it's very risky, Caen for example is so close to being an urban map that fits the forumla and works, it's only let down by the cutoffs which I've heard were fixed it's just that the correct version is not in the game.