That's the issue, Alli created a penalty out of nothing really and that can't be the sort of thing Southgate is relying on otherwise we'll get beaten by a decent team.
For me it was obvious early on that we weren't creating or pressing, so why not play Alli deeper? If we can't get the ball forward why not let him push it forward, it may not be his best game but it's better than those two being isolated up too.
We played with three centre backs but lost all benefits of that formation when we resorted to just parking the bus. The whole point is that the midfield and wing backs can push on and use the width created to try and pall apart their defence.