Yes please, I support this! Ideally they should simply be able to climb on top of these objects after a player (why can they jump tall fences but not get on top the hood of a car?!?) but since the navmesh completely avoids this kind of object it is probably easier to just give them a little more reach. That it is possible without breaking the game is proved by the PvZMod Customisable Zombies mod, I have been using that for years.

Said mod also gives them the ability to bash down doors if they are aware a player is hiding inside a house, this turns the PvE side of DayZ around and makes things A LOT more interesting. Instead of being a minor nuisance that players can easily lure into garages, or safely picked off from inside a building, zombies become a threat from which you can't escape that easily. The places where you can be completely safe are much fewer.