I might be pendatic here, but you should word this the other way around and say going from 75% to 74% in LE means taking 1% more damage
And in PoE going from 75% to 74% means taking 4% more damage
If you say it the other way around like you did it would actually not be exactly 1%/4% respectively but instead would be 0,99% DR/3,846% DR respectively
A while ago I made this table which shows very elegantly the difference in incoming damage based on different resistances values between LE and other games like PoE/Grim Dawn