I know the most likely answer I'm going to get is "Of course not, there's never enough pitching," but that's a boring answer and doesn't allow for much exploration of the question. To explore the question, the first key step is to identify the pitching that we can have a reasonable expectation that they might be ready to pitch on the MLB team by 2020.
MLB
1) L Carlos Rodon
2) R Dylan Covey
3) R Reynaldo Lopez
4) R Lucas Giolito
Other than Giolito, this group is very solid at the moment. There's still some SSS questions with Covey and some injury questions with Rodon, but it's not too difficult to see the top 3 guys on this list holding rotation spots in 2020.
AAA
1) R Michael Kopech
2) R Jordan Stephens
3) R Spencer Adams
4) R Carson Fulmer
Kopech obviously has immense potential and could be the ace of the staff in 2020, recent bad stretch notwithstanding. Stephens is an older guy, he'll be 26 very soon, but he's done nothing but produce at every level along the way. He's a guy I'd like to see get a crack at the MLB rotation this year to see what they have. Adams is young for level, which has been a theme for him throughout his minor league career. He just recently was promoted to AAA after a good run of starts at AA following a slow start to the season, so he'll likely be here the rest of the year. Fulmer to me is already in the "try to convert to high leverage reliever" category, but he's still starting at the moment, so it seems pertinent to include him here.
AA
1) R Alec Hansen
2) R Dane Dunning
3) L Jordan Guerrero
4) L Ian Clarkin
Remember Alec Hansen, that guy who was once in 1-1 consideration in the 2016 draft until control issues allowed the White Sox to pick him in Round 2 and he immediately put those issues to bed and showed the potential that had him in that 1-1 conversation for all of 2016 and 2017? He'll be back starting in Birmingham soon after he lost half of 2018 to injury. Meanwhile Dane Dunning has picked up where Hansen left off, doing nothing but consistently perform well against age appropriate competition as he has since being acquired from Washington. Jordan Guerrero and Ian Clarkin have had poor years, and may be best used as reliever converts.
A+
1) R Dylan Cease
I included Cease here because I feel he will be in AA by the end of the month. He's been great at this level, and his stuff gives him ace level ceiling.
Given the above information, I think promoting Stephens, Dunning, and Cease as soon as it is feasible. For Stephens, this season may be his only chance to prove himself worthy holding a rotation spot given his age and the ensuing logjam behind him. Dunning showed us a full season of A ball dominance in 2017 and has followed that up thus far with a half season of AA dominance. He doesn't seem to have much left to prove in AA and isn't very young for the level. Cease has also been dominant at A+ and appears to be ready for the test of AA. But what if Rodon, Covey, Lopez, and Stephens all stick as starters? That leaves 1 rotation spot for the likes of Kopech, Hansen, Dunning, Adams, and Cease, but more than 1 will be needed for this group. Do you trade one of the established starters to replace them with a guy that fits the timeline better? Do you trade some of the prospects for bats? I'm interested in hearing the board's thoughts on this.