I have never had a team with all relievers, but I have had a few teams where I only had a couple of pitchers you could consider starters. As stated above, as long as they can cover 1450-1480 innings pitched per season, it should not matter.
My team in Dirt has three starters and the rest of the staff are effective relievers and it's a top five staff in the World.
I had three starters -- one of them has won the Cy Young the last two seasons; the next one has above-average ratings, but 50 stamina; the third guy has below-average to average ratings, but high stamina. I have the CY Young guy set to a pitch count that is 20 pitches above his stamina, the other two guys are set to a pull rating of 5 and set to 40 pitches. This way, my best starter pitches the most innings, my other two starters get pulled once there they get in trouble and my relief pitchers take the larger burden of the innings on the season by design.
One thing to consider though is the use of those pitchers that only give you 60 innings a season. If you have too many of those guys, you might want to consider trading some of them. I only say this because you don't want to limit your lineup's use of effective platoons because you need to have 14 pitchers to cover all the innings.
8/3/2020 6:52 PM (edited)