A little cherry picking to do this after the best sustained offensive stretch in a long time, but using full year numbers going into next year is starting to paint a pretty appealing picture on the offensive side of things. The middle of the lineup needs help, but the bottom of the order is far from the black hole it was for most of the year. Projected lineup based just on the current roster:
Current fWAR/Projected full year fWAR/wRC/wOBA/xwOBA
Nico 2.9/3.4/96/.303/.312
Dansby 3.5/4.1/97/.306/.331
Happ 3.6/4.1/128/.351/.354
Seiya (DH) 2.8/3.2/133/.359/.340
Busch 2.1/2.3/116/.333/.320
Paredes 2.9/3.4/117/.328/.306
Cody (RF) 1.6/2.0/107/.321/.295
Amaya 0.5/0.7/82/.283/.299
PCA 2.2/2.5/91/.296/.286
A little lucky overall on the wOBA v xwOBA side of things, but overall I think you pencil 5 guys in for more than 3 fWAR not even including PCA, Busch, or Bellinger (ranked, by me, in order of how likely I think they are to get there). There were only 75 of those players last year so the good side of the math is in terms of quantity we're clearly above average there. Actual elite quality is obviously going the other way. 44 guys last year over 4 fWAR and I wouldn't bet on any specific player above getting there, to say nothing over 5+ fWAR. That's bad. We've tried to throw mass competency at the wall for the last two years and we end up in the low to mid 80s. Not enough.
Thankfully we have a couple things working in our direction there:
We have money. Hendricks, Smyly, and the departed players at the bottom of the roster are soaking up $57m in salary this year and outside of maybe like, Mark Leiter, we have to worry about replacing none of them. If Bellinger opts out, even better (my opinion).
10 guys for 9 spots is fine, and there are elite options for that 10th guy. Go pry Tucker away from Houston (and then sign him), prove everyone here wrong and get Soto, trade for Vlad and send Busch to the Ben Zobrist school of defending. If you don't go that route, find a third ace.