Quite a number of changes from DA:O create that problem. Enemies close faster, somewhat, but part of it is the distance at which contact is established. Every battle in DA2 is a series of ambushes, first by placed enemies you can't engage until you're at a certain distance, then more ambushes from enemies who magically appear at point blank. That's part of why point 2 was there - initiating combat at range meant a buffer zone to control the crowd. The enemy count is problematic because there aren't anywhere near as many effective crowd control abilities, and those that are run into the problem of recharge time versus respawn rate.
The whole affair reliably degenerates into a cluster****, in essentially every encounter. More guttural and faster paced, perhaps, but it's still lacking most of the tactical depth of the first one.