The problem with the warden without reach is that you will mark your opponents, and then they'll just shift one space away, outside the reach of your weapon, and attack your allies in spite of the mark. They suffer a -2 penalty, but that's all. After they attack you can use your mark ability to drag them back to you, but next round they'll just wander off again.
Remember, when you drag them back with your warden's Grasp ( i think thats the name) they also get hit with slow and can't shift....so they tend not to wander off...not without provoking your OA's, plus they can't wander far while slowed. I've used it on adjacent foes when they took OA's on an ally (who was running away to heal) just so they couldn't chase them when their turn came around. (Also, it never misses, unlike warden's fury which i seem to have difficulty hitting with, just luck really) Combine the slow,/can't shift with difficult terrain (say with winter's herald), and they're stuck close to you. I have a reach weapon as a back up, but i've never needed it to do my job.
reach wardens are a very good build, but not the only very good build.