Invisible walls were pretty much invented back when systems and PCs were too weak to have a large map. Even warband had invisible walls on the DTV maps before, but only on the border of the map so it didn't go on forever. Keeping that in mind, invisible walls should NEVER be used to keep players in check, and in all honesty, a player should never actually interact with an invisible wall. They are just there in case a player gets lost or tries to run away from the battle or what have you. An invisible wall on top of a fence, while still a cop-out, at least makes a LITTLE more sense, since the player will just assume that the fence can't be hopped, and move along.
Contrary to what you may believe, you nerfed the whole strategy thing in dtv. Sure, many maps were just pikers on a roof / in a hut stabbing away. Okay, I get that is exploiting, and it is honestly boring as all crap. I never partook in such events, always being a fan of the "glory charge." Take a map like istiniar for instance, one of, if not the, best exploit map. If you simply removed the hut, its a perfectly okay map. The archers can stand in their little barn in the hay, but what you seem to have forgotten is that bot aiming is more accurate that any human players'. Headshots happen 24-7. If you have a couple archers in the barn, maybe a piker or some other melee, they are far from invulnerable. Heck, they usually die first since they stand mostly still while us melee players are running all over the place.
Still think istiniar is too cheap with the barely-exploitable barn? fine... take that out. Now you have a fun map where archers kinda get shafted but melee is happy. But NO, you couldn't stop there... you instead made it a straight bowling alley, where we are the pins and the AI comes in like a bowling ball moshpit of death. And you say there is more strategy now? HAH! You can;t even go your separate ways to divide and conquer... the AI comes in one blob and stays in one blob the entire time. And now all you can do is S key... were A and D too OP you had to nerf those as well? FFS, DTV was fine with the lack of attention it had before... the buff to bots when they could block was greatly appreciated since it made it more challenging. Now the 'new challenge' update is total dumbassery to the point of borderline insanity.
So you say it encourages teamwork far more than before, right? THAT is the argument that you choose to go with, other than removing exploiting? Well let me tell you something, DTV is full of people who either want a break from all the tryhard modes (and bitching and shittalking that comes with the territory) or the occasional peasant who simply can't manage to kill anyone in pvp until they get their skills up. And DTV was great practice... taught how to block really well. Rarely would a clan join DTV to steamroll it, since no one who is a serious player in a serious clan would try to steamroll anything other than siege or battle (and the very rare rageball). So in other words, while many of us became friends from relaxing in DTV (no shittalking = nicer environment = friendlier people) there are many strangers, many not used to working as a team. And yet you want us to come with a full-sized shield wall, all sitting in the same TS dishing out orders left and right in order to win now? Not everyone is a shielder and no one is going to leave and come back on a shielder alt simply because DTV is lacking in shielders... you want to play the class you want to play, simple as that.