It makes sense to do that, if you have all combat information grouped together, including spells.
I prefer 2 pages, front and back, so one sheet of paper with printing on both sides.
Characteristics, Attributes, Skills, Spells, Hit Locations (where used), Name/Background, combat information
It makes sense, otherwise you flip the page over when working things out.
Constant erasing is a problem if you wear holes in the sheet. We tend to print sheets our every so often and change skills a little bit. It means updating the online sheet to match the paper sheet, but that is normally quick and easy.
It makes sense, especially for allocating skills. I have a sheet with skills on the left and amounts on the top, so you can allocate points to each skill and have a running total for each skill and each points pool.
Which is good. Most people prefer their own character sheets, anyway.