My understanding is that most troops, when they are deployed, have a self-protection aspect to them. You run a team site, and that team site is patrolled by Canadian troops. My understanding is that most of the time you don't tend to rely on other troops for the immediate physical protection of your own.
Where I've seen that in action, troops have protected each other fairly well. In eastern Congo there have been deployments of one nationality towards the team site of another, and those are usually the highest priority to the mission. When you're talking about triage and decisions to deploy troops to protect each other, in my experience, the decision to protect the other UN entities almost always comes first.