IPhone Set up for small to medium size business to be used by employees

Been looking at answers related to business giving IPhone to it's employees for business usage and related problems (e.g. https://apple.stackexchange.com/questions/19966/small-business-iphone-deployment ), it seems the simplest way is to just hand them the phone to be set up by the user themselves. The only problem would be if the phone becomes connected to personal apple id rather than an apple id of the enterprise owning the phone then there might be problems when the phone is being retested and passed on to the next employee. Or is this completely false? Sorry I am a windows user.