This season's arena team composition

Hey guys,

I'm usually independent when it comes to optimal arena teams for each new season, but this time I'm actually quite unsure how will my team hold up defensively, so I'm open for your criticism and suggestions. I have quite a lot of units, so I won't be posting my options, since I would just have to spam you with screenshots. I'd just like to know if there are theoretically any problems that could be patched up by a different unit type.

Delthea +1 +spd -atk - standard build using her tome to buff others + drive atk and fortify res seal.

Black knight +1 - main tank and DC unit. Standard fury + vantage build with distant def seal and ward armor.

Vampire Henry +def -hp (S summoner support) - meta unit with bowbreaker to deal with Reintards and bow users. Iceberg as a special, still undecided A slot, armor march and atk ploy 2 seal.

FrankenJakob +atk -spd - standard brave bow + death blow build with ward armor and panic ploy 2 seal.

I feel that this team should cover most of the matchups - Delthea for reds, BK for greens and reds that Delthea can't safely kill, Henry for everything blue and archers, Jakob as an all-purpose nuke because only a handful of units have survived his brave bow nuke (too bad that Delthea can't buff him with her tome).

I'm probably mostly unsure about Delthea's presence and was thinking of switching her for Brave Lucina (neutral), who's using the standard semi-support build. She'd be able to buff the other heroes more reliably and could also add a speed buff to the mix. Do you think that the AI could handle it?