Liverpool squad and club were performing about at the same level as United currently are when Klopp as appointed.
In the 5 years before Klopp took over they averaged 64.4 points in the league, scored 65 goals on average, and their average league position was 5.8. All these numbers are inflated by the freak 2nd place finish where Suarez was Balon d'Or level and they scored 101 goals. Take that out and they averaged 59 points, 56 goals, and 7th place.
United on the other hand averaged 66.6 points (higher than Liverpool), 62.4 goals (3 less than Liverpool), and the average league position is 4.4 (higher than Liverpool).
The season before Klopp took over, Liverpool finished with 62 points (2 less than United last season) and scored 52 goals (5 less than United scored last season).
That is what the numbers say.