Any putz who can't climb 5.4 and I don't care if it's dry, wet, sandy, snowy whatever needs to spend more time mastering body position and natural climbing movement in a TR situation before getting on the sharp end... single pitch or multi. 5.4 should not be hard.
Bolt a 5.4 finish to a 4th class route... why stop there? Let's blast it and put in a wheel chair ramp!