I won't even get into a fight with anyhow, you never know what they have in mind for you and what if something horrible happens to you as a result of the fight and you lose your life or other parts of your body that's of importance to you, like become disable for no good reason.
If using my friends account will increase our chances of winning or give us higher percentage on the win because of the bonus he has or any other reason. I won't mind using his account bit before we send the money into the account, we'll have an agreement in place.
The agreement will include how the money will be shared to avoid future problems like what this thread is about, people are greedy and your friends might want to use because it's his account to take advantage of you so it's better we have an agreement and witness.