Large businesses deal with this issue often because 1) they want to make sure their employees are on brand and 2) they want their employees to act as ambassadors for them online, which is a good thing.

To make it simple, I would hire someone to write the post(s) for them – links, hashtags and all – in a Word document so all they have to do is cut and paste. The document can be shared on a drive and emailed out to everyone when ready.