i just dont get why they didnt put em in great kilts, i mean they are basically the same thing except the great kilt is double wide as opposed to single-width.
That would still be historically incorrect. From Matt Newsome's web site:

Despite what you saw in Braveheart the belted plaid was not worn in the 13th and 14th centuries. The belted plaid costumes worn in that movie were not even very good representations of the belted plaids. I honestly do not know how the costumers could have claimed to have done any historical research—they simply designed a garment that they thought looked both Scottish and medieval.
See: http://www.albanach.org/kilt.html

Cheers,

Todd