I can’t see a scenario where Roger defeats prime Whitebeard. Whitebeard is better than Roger in every aspect and has Haki comparable to his.

He Got a WSM Title on top of everything solidifying this.

“He never defeated Roger”. He never had any reason to do that unlike Garp.

“They both fought each other to stalemate”- that fight is not even a serious one.

“Sick roger clashing equally with WB”- i think he is not affected by it during his battle because of 1. Crocus statement. 2. Neither Roger nor his crew mentioned it during their 3 day battle with WB battle. 3. I don’t think anyone who got sickness can defeats marine NPCs, fight WB for three days straight and remain unaffected. 4. We don’t have either statements or visuals to say his fighting is affected by his sickness during their fight with WB.

Remember Sengoku called WB “World’s Strongest man” while Garp standing next to him.

This means two things. 1. Old WB is the strongest ( which is not true ) 2. WB used to be the Strongest and sengoku doesn’t know about his sickness.

Both of these puts WB above Garp.

I still say Roger has better Haki than WB, but difference is not so huge.

Does that mean Roger defeats WB? No. unless you think - 1. His Haki can negate WB’s Devil fruit ( his Haki is better but not enough to do that) 2. His haki can straight up negate his physical strength, durability and endurance.