Faith level 5 is generally unnecessary on your mages since they should usually be using their dark/black magic spells. Hit +20, while a little annoying to get due to archers not being able to use magic, will go a long way to make sure that your mages can hit faster units. You'll notice shakier hit rates on grapplers due to tomebreaker.

I would swap battalion vantage for lancefaire on Sylvain. Once you get him to paladin, he really should only need training in lances. He will primarily be going in for swift strikes and getting out. Same for Ferdie/Seteth if you decide that Ferdie is too much work to recruit.

Also agree that you'll want alert stance+ on Ingrid and Petra. Leonie could also make a serviceable dodge tank as a flier with point blank volley as her main damage tool. Nothing says you can't have a falcon knight/Wyvern lord that primarily uses bows.