Presidents have had similar powers in many presidential republics. For example, Finland was like that until ~30 years ago. Ultimately it doesn't matter much if

Presidents have had similar powers in many presidential republics. For example, Finland was like that until ~30 years ago. Ultimately it doesn't matter much if the head of state is a king or a president. It doesn't even matter that much what they could do in exceptional situations, or whether they inherited their position or were elected to it. What matters is the tradition of running a normal democracy. If the elections are fair, if the ones who lose their power step down gracefully, if there is a peaceful transition of power, and so on. If you have a tradition of that, adapting a different form of democratic government is not that hard.