Do all brothers deserve the same share of business profits, despite the varying periods of their arrival and work in the nascent shops, knowing that some of them would travel and return to work?

These brothers either entered as partners (Mudarabah (definition)), in which case they are entitled to an agreed-upon percentage of the profit. If the Mudarabah becomes invalid, the worker is entitled to a fair wage (اجرة المثل) or a fair share of the profit (ربح المثل). Or they entered as employees, in which case they are entitled to the pre-agreed wage. If the employment contract becomes invalid, the worker is entitled to a fair wage (أجرة المثل). Their right upon their departure is determined by their status (partners or employees) and the agreement concluded.