In my humble opinion, central midfielders can score a lot in a 4-5-1 with a lone striker on support duty. One midfielder should be on advanced playmaker support / deep lying playmaker. The goal scoring midfielder should be central midfielder attack. They should be covered behind by a DM. Playing mentality for the team should be attacking. Philosophy - balanced. Decreasing run from deep and decreasing the creative freedom of full backs will make them play cautiously and should help you against counters.
I used the following players in the cm attack role in rotation: Tom Cairney, Thiago Alcantra, Ilkay Gundongan. Over one season, Tom Cairney scored 13 goals, Thiago 5 goals and Ilkay Gundongan 8 goals. So that makes it 26 goals for the season from the CM- attack slot.
They generally score the goals by the following methods:
1. Lone support striker holds up the ball and passes it to the CM-attack who is making a surging run past him. He is one on one with the keeper and if he has decent composure, will score... Cairney used to excel in this.
2. By making late runs into the box, they end up being unmarked and are so well positioned to score from close range, especially when a winger / inside forwards is making crosses / through balls into the box on a counter. Gundongan used to excel in this.