It might be a characteristic of that particular production run. During my early experience with the "old" Gortex Targhee I found a bunch of shoes that had a problem with the collar of the left heel. A few months later it was gone.
The supersized toe box of the Keen shoes is one reason I was drawn to them. I wear a fairly severe orthotic to alleviate my plantar fasciitis and the Keen shoes have plenty of room in the arch to accommodate the insert.
With the low top I wear a pair of lightweight REI gaiters. That keeps out dirt and incidental water from wet grass.