The saying that 'fellow workers make the worst enemies' couldn't be truer.
Whenever you encounter a peer, regardless of whether they are friend, foe, or a completely unrelated passerby, people need to establish a pecking order at first glance, and for those whose profession is warfare, this is especially true.
For those who live by combat, training levels and combat skills can not, of course, be discerned from appearance, but the quality of one's equipment can be seen at a glance. While the quality of equipment doesn't entirely represent combat effectiveness, it is still a part of overall capability, and superior equipment certainly offers an advantage.