Surprised they haven't already added these tanks. It took just a few minutes to make a very basic line from Tier IV to VIII. Also, the light tanks will not have Scout MM due to the upcoming extension of LTs to Tier 10. It's a very rough draft but I will get into more details in later posts.
Starting from the T-70 at Tier III
IV V VI VII VIII
K-73 ASU-57/76 ASU-85 PT-76 Obj. 906
TD TD TD LT LT
Branch merges into the T-54 Lightweight which will be at Tier IX in the future.
The ASU-57/76 is two designs combined into 1 tank for the sake of compacting the line.
ASU-85 was developed from the chassis of the PT-76, and the Obj 906 is a beefed up PT-76 with a 90mm D-62 gun.
I will make new posts to tell the details of each tank in the branch later.