Thats just the luck of the draw. As has been pointed out, and luckily thanks to Gina Millar, the balance of power does not fundamentally change with the person sitting in the PM seat. The overall position of the Tory MPs will not fundamentally change. Boris if anything is more likely to crystalise the MPs harder into camps, and if he tries to move to more anti EU he more likely to push more middle ground ones to fight against for example a hard crash out. Hes also far less likely to manage to get Labour support.