Yeah good point. When considering this, I do think that ending at Hong Kong could work, because in Shenmue II that chapter ends with the chase sequence between Ryo and Ren and it could probably be embellished in the anime. The cliffhanger would be the anticipation to finally meet Yuanda Zhu to find out more about your fathers death, and your new shady partner, Ren, who you're not sure you can trust. I'm also just going by the fact that from what we understand, the anime would cover "part" of Shenmue II, so I would be very surprised if we see Guilin at all. And if the plan is to re-add cut story beats I imagine it would be stretched out a bit longer.
Maybe trying to map out the episodes to chapters in games might give us a pretty good outline? When I tried to break down S1->S2 Hong Kong -> S2 Kowloon it seemed like it would move really quick. Not just the story coverage, but consider how many characters would come and go throughout the season. Here's a quick example (this is mostly arbitrary and just for demonstration and you can give or take 1 episode per chapter)
If it ends after Hong Kong:
Episodes 1-6 covers Shenmue 1
Episodes 7-13 covers Hong Kong
If it ends after Kowloon:
Episodes 1-4 covers Shenmue 1
Episodes 5-9 covers Hong Kong
Episodes 10-13 covers Kowloon
Maybe it sounds much bigger since we're familiar with the games and how long it would take to get through these story beats, while they'll flow perfectly fine in an anime?
I think Shenmue 1 could be condensed down quite a lot with plot points like Charlie being scrapped, but Shenmue 2 has a lot of meat to the story and would require quite a lot of screentime.
1. Arrive in Hong Kong. Lose bag. Regain bag. Joy takes you to guest house.
2. Look for LT, arrive at man mo temple, told to learn about the Wude.
3. Learn 2 wude.
4. Learn 2 wude.
5. Temple service. Learn about Wulinshu. Obtain Wulinshu.
6. Learn about Chawan signs. Meet Zhang and get told about Ren.
7. Infiltrate heavens hideout. Get ass kicked.
8. Wake up on the boat with wang. Find / chase Ren. Leave for Kowloon.
9. Arrive in Kowloon. Look for Zhu. Get taken prisoner by DN.
10. Escape. Follow Yuan. Free Zhang.
11. Learn about Ghost Hall Bldg. Meet Zhu. Zhu gets taken.
12. Try to enter YHB. Learn about scout. Impress scout.
13. 2 fights.
14. 3rd fight and get told to meet scout the next day.
15. YH building upto Baihu.
16. YH building upto rooftop.
17. Defeat Dou Niou. Learn about mirrors from Zhu. Leave Kowloon.
18. Arrive in Guilin. Rescue Shenhua. Sleep in cave.
19. Continue on to cave.
Looking at all of that, I retract my earlier prediction that they will finish Kowloon in the first 13 episodes. I think the most likely point would be after the Ren chase scene.
Maybe season 2 will cover Kowloon and Bailu?