An MLB article today says NY improved their rotation, but all I see is a "favorite" who replaced their #s 2, 3 and 4 starters with injured guys and hopefuls. Nothing guaranteed, there, either.
When looking at who were the Yank's innings eaters and best SP'er over the last 2 seasons, Tanaka, Paxton and Happ are easily in the top 4 in both areas.
IP 2019-2020
230 Tanaka
211 Happ
171 Paxton
143 German
107 CC Sabathia
103 Cessa
fWAR
4.1 Tanaka
3.8 Paxton
2.0 German
1.9 Happ
1.5 Cole
0.4 CC
You are right, nothing is guaranteed. Their rotation could get worse, especially if Sevvy does not return to form after returning mid season.