Sure. That makes sense. But then you're in a situation where you have to push hard to max out the Executrix's abilities, and Prestige does not come in quickly.
Also there's no healing from Executrix, so just remember that. It's not bad, because you have other abilities and should be able to take enemies out more quickly, but it's a different style of play that you should be ready for.
So if you're going to make the switch, stop investing in Home1 prestige right now, keep barreling ahead with Tarkin, and pay close attention when you start using him as your Fleet Commander so that you can get a feel for how the rhythm of the battle has changed. Adjusting your instincts will be important.
Also, your fleet commander has to be g11 **minimum**. So even if you take Ackbar off the list, you aren't going to make gearing any easier. Because now instead of taking Tarkin from g9 => g10 and Ackbar from g10 => g11, you just have to take Tarkin from g9 => g11.
I am not saying that's a bad plan!!!!! I'm just saying that you should be ready to take Tarkin's gear higher than we first planned.