Quote Originally Posted by HoreTore
Uhm... History is full of examples of smaller powers attacking their much bigger neighbors. A few examples:

- Scotland attacking England
- Portugal attacking Spain
- Turks attacking byzantines at manzikert
- Various italian states attacking the HRE

Just because a kingdoms neighbor was more powerful than you didn't mean that they forged alliance, or that the small power even wanted an alliance/peace.
Historically, all the examples you've made do not enter in the "thrice your army" statement.

Scotland became part of England hundreds of years after the first wars, while Portugal, Turks and those italian states still exist under one united nation (when Italy was created, all those small states still existed).

Those examples show how the smaller states had the chance to not being destroyed even by waging war.