I think your only realistic options, if you want to stay in the house, are to either buy your brothers out or have them agree to you renting it, with two thirds of the rent going to them.
Ultimately, if executors can't agree, one of you will have to apply to the courts for a decision, or to have an executor or executors removed. It's expensive and it's unlikely a court would rule against a will, so if the will says the estate is to be split three ways you, or a court, will have to find a way of achieving this.
I've dealt with probate twice in the last two years. Did everything myself. The first was straightforward. The second contentious and it's still rumbling on and is similar to your situation. I got legal advice and was told the above. The solicitor was very pragmatic and advised heavily against legal action if at all possible.