You don't need a slider if you can remember to pay attention. But as already stated some of that depends on the variables. Bed length is not an issue. Cab-to-axle (CA) distance is , GM is the longest, Ford just a little less and Ram is the shortest. Then fiver cap design is the other big factor.
Regardless of setup, you will not get into trouble making a 90 degree forward turn, the steerable wheels of the truck can only turn about 36-37 degrees max. So, a 90 degree turn at full steering cut will only result in a truck to trailer angle of around 45 degrees. You cannot make a 180 degree turn at maximum steering cut, but you can make a 180 degree turn at less than max. steering cut.
Where you will get into trouble is when jockeying back and forth to get into a camp site. That is if you try and get by with the least maneuvering. In 30+ yrs, I've never found a spot I couldn't get into if I was willing to take a little extra time maneuvering. Four SB trucks and 7 fifth wheels and never made contact between truck and fiver.