Managing retinues and

[Viking]

First, you have to make sure that the characters are in the same army/city.

Then drag the retinue you want to exchange from one of the characters, and drop it on the the picture of the character you want to give it to.

To give your family members management skills, you should try to build academies, or the temples that give retinues with managment improvements.

[Nelson]

Any retinue is limited to 8 persons. If all leaders present already have 8 you will need yet another leader with less to facilitate the switching.

[Ldvs]

Perhaps you'll pay a very careful attention to this at the beginning of the campaign but I doubt you will later, since your economy will most likely be wealthy and this micro management might bore you
Not to mention that once you build academies as Viking mentioned it, you won't need to transfer them since your generals will have ancilliaries aplenty.

[katank]

A very good thing to do is to have governors regularly convene in an army and trade retinue members about. You can stick the old guys with all the useless retinues and give the valuable ones that they have to the young'uns.

You can also use ancillaries to manipulate which ones are your generals which are your governors etc.

[Kekvit Irae]

Temples can often churn out great priests at a surprising rate. The best ones to get for a governer are the ones from the Temples of Trade (Hermes, etc) if you want a boost in management.
View frogbeastegg's thread on RTW for more info on what temples give whom (in the appendix) here: https://forums.totalwar.org/vb/showthread.php?t=38382

[Nelson]

It behooves anyone to get the right retinue to a gov who will manage a key troop raising city because all of the unit cost reductions stack. When a leader’s unit costs reach 50%, not only do troops cost half as much but the two turn builds like elephants or silver shield pikes take only one turn.

[Ahmose]

It behooves anyone to get the right retinue to a gov who will manage a key troop raising city because all of the unit cost reductions stack. When a leader’s unit costs reach 50%, not only do troops cost half as much but the two turn builds like elephants or silver shield pikes take only one turn.

Really..
very good thx for the info.