Good points, but I think the rotation issues go beyond just the last 2 spots in the rotation.
Sale's ERA more than doubled. He's allowed 5+ runs 8 times and 4+ runs 13 times out of 25 starts. Last year, he let up 4 runs once and 6 runs once. All his other starts were 0-3 runs allowed. (Runs not ERS!) 2 out of 27 vs 13 out of 25.
Price's ERA jumped about 80 points. He's let up 5 or more runs 3 times and 4 or more 7 times in 21 starts. Last year, the same but in 30 starts not 21. 7 out of 30 vs 7 out of 21.
ERod has lasted longer in games, but his ERA jumper 50 points. He has 6 games with 5+ runs allowed and 11 with 4 or more out of 24 starts. Last year, he had 6 starts with 5+ runs (all with exactly 5) and NONE with 4 runs allowed out of 27 starts. 6 out of 27 vs 11 out of 24.
When you have your 4-5 slots sucking badly and your 1-3 slots dropping significantly from last year, it's hard for any manager to manage wins.
2019: 31 out of 70 starts with 4 or more runs allowed.
2018: 9 out of 84