The problem with the maps you've described is that they're all Deathmatch style maps. With those maps, players are always respawning, and have a good chance of getting to a gun.
Imagine that one player gets to an M4 and shoots two other players before they can reach anything (we'll say they started with a glock). In deathmatch, those two players would then respawn elsewhere and again have a chance to get to decent weapons and take out the guy with the M4. in CSS however, they're just dead.. they don't get that chance. Basically, this means that whoever gets the best weapon first wins, which isn't very fun
The map crossfire, while my favorite HLDM map, is incredibly poorly set up for CSS. The choke points are all wrong with very few points of entry between main areas, each of which could be easily covered by a team camping one or the other areas. The courtyard area has numerous levels and rooms that simply aren't necessary for CSS. None of them would ever get used, or they would be used as too many hiding spots with easy and quick access to the main courtyard. Likewise, the helipad outside would just be a sniper-fest.