Lachesis > Beowulf or Alec.

Reason being, Return Staff spam. 2 uses of Return + 2 Lives = 1 level up.

Her competition? Ethlin and Aideen.

Ethlin: She leaves after Chapter 3. Other than for ranking, this isn't really a good investment.
Aideen: Lol Hi Priest.

Lachesis doesn't have much trouble getting it and repairing it either, she starts out with 10k Gold, access to the Thief Sword and heck, just 1 full village is enough to repair 10 uses of it. It's basically her Elite Ring.

Beowulf on the other hand requires Elite Ring to speed up on his leveling and everybody you're seriously using on your team wants that besides Sigurd.

Let's say they're both promoted and level 20 at the start of Chapter 4 (personally I find this unlikely for Beowulf but whatever).

http://fea.fewiki.net/fea.php?character=lachesis&game=4
http://fea.fewiki.net/fea.php?character=beowulf&game=4

Beowulf's only leads are just +10 HP and some SKL while Lachesis has a 2.3 DEF lead and a 7.3 RES lead which is relevant in Chapter 4. Lachesis can also work around her weaker durability during the player phase by either using Magic or a Bow and then switching to a Sword or Magic when ending her turn. Beo only has Magic Swords for range so it's either that or eating a counter-attack during the player phase. Lachesis will continue to have superior combat as well as having Staff utility.

Alec just has more availability and an inferior result compared to Beo.

I was kind of leaning towards Lachesis anyway.

Bumped Alec down a tier, too.

She could probably go above Fury too. Short version of it being that Fury's not gonna do much (if anything) at all during chapter 2, she wins Chapter 3 but loses Chapters 4 and 5 since Lachesis can promote at the start of C4 and Fury won't until perhaps late C4 and Lachesis wins when both are promoted in both offense and Staff utility.

didnt object on IM

dont object now

EDIT: Actually I've got a problem. I don't know whether to drop Fury down a tier or to bump Lachesis up one.

Well, I guess we need to decide whether there's a tier gap between Ethlin and Lachesis.

Move Lachesis up.

Ethlin's just mobile healing for 4 chapters (Prologue - 3) while Lachesis is healing for 2 chapters and then ends up one of the best combat units for C4 and C5. I don't think that warrants a tier gap.