Hired two, when is the right time to fire one?

So last night, thanks to the excellent and meticulously detailed guide provided by Antonio Luna , I managed to do HRE in 39 moves and pick up both Isabela and Sakurako.

However, the presence of Isabela in the lineup means that Carteaux - at 110/10 - has now pretty much outlived his usefulness (i.e. do I really need three artillery generals?)

I had originally intended to regroup him immediately and boost Isabela up, the better to play sooner with my shiny new toy (and run for Victoria/Lan), but on the other hand there is much to be said for grinding her for a few levels first, using the Trafalgar grind and my cities-surrounding medal grind for combat experience and Chain the Beast for nobility, until such time it becomes tiresome (level 7 or thereabouts). At that point letting her feed on Carteaux will arguably have a greater benefit. 

Or is that not the way it works?

Hints are also appreciated from those who use Sakurako and like her, with regard to both her tactical application and her training.

Thank for the advice, Antonio Luna

Latour (infantry trainer) has just turned up in my academy. Is Sakurako worth training in infantry at all, or is she better off to be given a cheap cavalry trainer and turned into a companion for Dumouriez until Lan arrives? Dumo is 5* right now with lots of rank and nobility, and helped immensely in the Isabella/Sakurako campaign, so I don't want to let him go until the ultimate cavalry general arrives. When I get Lan, I will probably regroup Dumo into her immediately.

The thing I notice about Sakurako is that with the exception of Banner, EVERY SINGLE ONE of her skills is directed to avoiding evasion of terrain against all of infantry, cavalry and artillery. This coupled with her movement stars makes her an excellent fighter in rough ground. Most people seem to use her as a cavalry general and it's easy to see why - the ability to kill and conquer in the one turn. But in campaign mode, it might be worth having her a little more powerful on infantry at times. Difficult choices.

Alas for me, I regrouped Fatimah when I was still a four-slot player. Now that I have taken the plunge and bought slots, I regret this deeply. For playing small nations or developing medal grinds, arch and econ is a valuable combination. However, it isn't a good one for rushing because her talents make you want to use her to capture/steal and upgrade cities and hang around in the bigger ones when generals have better things to do.

When I eventually finish this game on the kindle and have bought every item and won every conquest as every nation, I might yet start over from square one, choosing my generals more wisely from the beginning. And this time I will open all the slots and keep all the princesses.

For now it is perhaps better that Sakurako act as understudy to Dumouriez. It's really not that expensive to boost her to five cavalry stars and that will give me a very fast and very hard-hitting unit with which to get to cities and take them quicker.

I regrouped Carteaux into Isabella and she is now 98/8. I hated to part with him because he's served me well, but now that she's here his time really is at an end.

Regrouping Dumouriez into Sakurako would make her 110/8 and give her a third cavalry star. However, I keep telling myself I should save him for Lan.

Advice?