Play an E maj chord with your
pinky on the 5th string 2nd fret now take your
ring finger a place it /or tuck it behind your pinky on the 4th string 2nd fret! Now take your
2nd finger and place it on the 1st fret third string.Now this leaves your 1st free to barre any chord as you slide up! ALL major barre chords are based on the E[Emaj] fingering. And to your question about your hand size no its not the size of your hands you have just got to train your fingers! use this pinky/first E chord method,I promise in no time you will train that littlle sucker.I hope this illustration helps

Now take your
index finger and barre all six strings and practice hammering into that F chord, slide to the third fret and hammer into the G chord,and so on all the way up the neck. Good luck ..... If you are talking about the way Jimi Hendrix plays his barre chords they are based on the F major chord with the
thumb rapping around the top of the neck to play the base note of the chord like this....