I wouldn't be about that. It definitely tips the scales too much. With 20 mana no mater where the enemy tries to run to nothing can stop immediate attacks. Just by the math r1 is 14 dice, folowed by 14 more? In fact this will widen the gap between 10 chanel and 9 chanel mages. Cuz a 10 channel can throw 2 boulders r1 AND r2. A 9 chanel mage cant. Not a fan.
I personally would not like starting in the middle. I love the positioning game. The tactical maneuvering. When you start next to each other you destroy the part of the game I love. Would be hard pressed to get me to try it.
I would love to test this. A well timed reverse attack (among others like Eye for an Eye, block, divine reversal, etc) could really screw with that attack plan. I am not going to give an opinion one way or the other about whether it would definitely be "less strategic", but I'm hesitant to agree with that assertion. I think the tactical movement would be just as important, there would just be a little less of an opportunity to hide in a corner for 5 turns turtling. I find that to be a good thing for the game, however that's just my opinion at this point based on theory.
Edit - Sharkbait was wrong, alert the internet.
I was misinterpreting the original idea. I was imagining starting in the middle zone of the two edges instead of the OP's middle centers. So, in my head, it would be interesting if one mage starts in the left column, middle row. The other mage would start right column, middle row. Still 3 zone separation, still room for tactical movement, and still a bit of build up room, though less pronounced than before.