Hi,
Below I have the images of two coins. Both have the same legends on both sides. Both are deniers issued around 1280-1287.
+ G: DVX: ATENES:
Cross pattee within circle; crescent in one quadrant
+ ThEBE: CIVIS:
Château tournois (stylized castle)
However this is a very notable difference between them - in the style of the lettering.
This one has the angular E shape

while this one I got recently has a rounded E

From what I understand the legends for both William I de la Roche and Guy II de La Roche are the same but this distinction isn't what makes it possible to tell the difference. It seems the E shape difference is just a die cutters preference - and both are possible for both rulers.