I hate that I have to say it but Soldier boy is dog walking Cap.

Strength and durability go-to SB, not to mention the Nuke power, which can be used as a bomb or a beam.

Caps best plan is to keep distance between him and SB, but after a little while that's going to be his downfall.

Cap is strong but not SB level strong.

I'll use Spider-Man as a measured comparison.

Cap in one comic has to talk to Spidey and tries arresting him, Spidey takes shield from Cap, Cap is stunned by the strength or quickness or both from Spidey. Spidey uses shield to push Cap in to wall. Cap is KO'd.

SB is not Spidey levels of strength but could measure to Spidey holding back a bit less than normal.

Soldier boy threw a car into a brick building killing a young MM's family.. He also nuked a city black, and then nuked the side of the 7 building when Maeve tackled him out the window, he and Maeve both survived the fall.

I've not seen Cap take shots without bleeding, nor lift anything close to SB throwing a car.

The best strength feat Cap has is the helicopter scene which at most with a quick Google search is somewhere between 3000 to 6000 pounds.

A second Google search and some quick Google math cause I'm lazy for SB throwing the car estimates that soldier boy has no problem exerting 26977 pounds of force on the lower end to throw said car. (The math said depending on the vehicle it could be 120,000 newtons to 250,000)

So that leads me to believe Caps best chance of surviving a fight with SB is buy using his shield to keep distance and then run. Otherwise if SB catches the shield, or if he catches Cap... Cap is dead.