While the various schools of thoughts are useful to know and understand, I reckon it's not always straightforward. There isn't a hard and fast rule when it comes to when to let kids try "allergens" prone food.
My best friend is really one those happy go lucky moms who parent by instinct and doesn't really adhere to such all the rules and her son is happy, healthy and beautiful with no health issues so far. I know parents who are extra careful with what their child eats yet he or she still develops allergies.