Normally a lawyer would let you know what would be the general compensation for the executor/guardian. 5% of total assets. They will put it in your will as well.
On the other hand, if you don't appoint an executor/guardian, the government will assign it for you. Of course, they will charge you from your assets to compensate as well. Therefore, the choice is either you choose someone or government chooses someone for you. What would you prefer?