# they went in any of their four directions

Possible meanings are 1) "their" refers to the creatures. AT: "they would go straight in any one of the four directions that the creatures looked towards" or 2) "their" refers to the wheels.

# whatever direction the head faced, they followed

Possible meanings for "the head" are 1) this refers to the winged creatures. AT: "they went in whatever direction the winged creatures were looking" or 2) this refers to the front wheel. AT: "they followed in whatever direction the front wheel went"