Oh, well. I simply remember Nowi@Gregor being able to 2-shot the Cavaliers, Myrmidons, and Mages on the join map in hard mode (axe people are limited and thrown into the sand). I cannot recall the exact damage output from those enemies, but I recall it being about a 3HKO on her at absolute base. I do not see the training being all that demanding compared to any other unit. Being able to 1-2 range and 2HKO at join time I think is more than can be said for a lot of units in this game when they first come into play. You do not need to feed her ANY kills at all. She will kill them herself. She only needs limited enemy density at first. At lv3, she quickly gains experience and has 50% skl, spd, res and 65% str, def along with 120% hp, and will continue to gain experience at a higher rate than the others since manaketes gain exp like unpromoted units.
As an example, in 7 levels, she has (on avg.) 26.5 hp, 16.55 def (w/dragon stone), 12.5 res(w/dragonstone). Her low HP is completely fixed in a short 7 levels. Very fast too when you think that enemies are at a higher level than she is at lv3, but already approximately 2HKO enemies. The speed problem is very short lived too (if not existent). Immediately with pairing (not really effort), she no longer gets doubled (really the only thing that doubled her were Myrimdons at join time). After you get a few levels, the continued pairings (speed support increases too), she will be able to double enemies routinely.
I do not see the reclass options being that big of a deal. Manakete is the only thing she needs, and so long as you kept the Manakete class the whole time, she'll be a fine end game unit. As enemies continue to get stronger forges and stats, its harder to find units to still be able to ORKO enemies and survive multiple hits. Especially at range since only Magic has affordable MT while Lance/Axe needs forges and only have limited uses. Additionally, you face enemy density that is filled with a variety of weaponary. Nowi has high enough hp, def, res (and no flying/mount weakness) near mid-late to tank all of those hits and ORKO right back at 1 OR 2 range. As example, I have gotten Nowi to lv30 by about chapter 17-18. A
LTC on hard has her at about lv25 after chapter 15.