China And South Africa Stamps Error In Size, Holes And Teeth?

hi to all my dear friends,I need help from stamp experts for this China and south africa stamps.

First of all,this pair of china stamps that comes together issued in 1989.A potrait and heroic of li dazhao(co-founder of chinese communist party in 1918).The series and number of this pair of stamps are J164(2-1) and (2-2) on each stamp.Obviously,Both stamps are in difference size,left one is taller and the right one is much shorter by 1mm and there are two missing perforation teeth missing on both vertical sides on the right stamp.There are only 16 perforation teeth on each vertical side instead of 17 perforation teeth normally on each side when compare with the same stamp together.Error size stamp showing on second picture and normal size stamp showing on third picture.PLEASE HELP ME TO COMPARE THE SIZE,COUNT THE PERFORATION TEETH ON FIRST THREE PICTURES BELOW.

1.Is this stamp size normal or considered an error?
2.Have you ever seen any CHINA stamp size which is longer,shorter,taller,smaller before?
3.Rare or common size for china stamp?

Lastly,there is another SOUTH AFRICA 3d stamp issued in 1949,the size which is shorter too and missing two perforation holes and teeth on both vertical side too.The perforation holes are 15 and teeth are 16 on each vertical side,normally there are 16 holes and 17 teeth on each vertical side.Seem the stamp is much shorter than a normal stamp.ERROR size stamp is showing on fourth picture and normal stamps showing on the last three pictures.PLEASE HELP ME TO COMPARE THEM,SEE THE SIZE AND COUNT THE HOLE AND TEETH ON THE LAST FOUR PICTURES BELOW.

1.Is this stamp size normal or considered an error?
2.Have you ever seen any SOUTH AFRICA stamp size which is longer,shorter,taller,smaller before?
3.Rare or common size for SOUTH AFRICA stamp?

PLEASE READ THE DETAIL AND ANSWER ALL OF MY QUESTIONS ON ABOVE.HELP IS ALWAYS APPRIECIATED.THANK YOU.