I'm at a bit of a loss to understand why someone's legs cannot give leg cues.
Are you trying to give them with your feet or heel? I've been taught to use my calf.
Also, I need my toes to point out about 45-60 deg to get my leg around the horse. If I try for toes front, it twists my leg around and pushed my knee into the horse, doing all sorts of bad things to my riding. Or I can move my feet forward some, like in the old west, and then my legs will fit while allowing my feet to point forward some and heels to go low.
Riding my gelding:
As for the difference between western and English, modern English seems heavily influenced by jumping. Up till the late 1800s, jumping was done deep in the saddle. The Italians figured out then that getting out of the saddle made it possible to jump much higher, and it seems that English saddle design and style of riding has been adjusted to meet that goal.
Jumping and dressage (from an outsider perspective) seems to need constant communication between the rider and horse, so the horse is 'on the bit' to allow a constant feel. The English rider wants to direct the horse's movement.
Western riders rely more on the horse's initiative. The rider sets the goal, and the horse figures out how to achieve it. This frees the rider up to rope, or watch the cattle, or to just think about something else while the horse feels his way across rough country. Real western riding cannot assume smooth ground. Two LS cowpunchers feeling their way over a bad trail. LS Ranch, Texas
, 1907 Cowboy [possibly Elmer Sager] working the herd and cutting out a steer. Shoe Bar Ranch, Texas
BTW - notice his toes pointing out!
From an excellent collection of western riding pictures taken in the early 1900s: Erwin E. Smith Collection Guide | Collection Guide