I think the general rule for these decisions is to choose two or three channels and do them well. If an organization tries to force themselves to use too many channels it may be difficult to attend to them and keep them fresh.
You could start with the channels people in your organization are comfortable using already. That will remove the learning curve trying to get the right tone as to what and how you post. If these couple channels are getting good engagement and generating feedback and comments, stick with them. If it’s not reaching the audience you want, you could venture into another channel and see if that strikes a chord. BP