True and that is why he isn't really fit to lead, because sometimes you have to make tough calls, like sacrificing troops in order to create an opening knowing that they are getting slaughtered as a consequence. Tirion greatest weakness is that he won't even considering something like that.
If your personal values potentially endanger the whole planet, you should take a step back and reconsider sticking to them, racial leaders have to compromise their personal morals all the time.In the end you can't be "honorable when the situation afford it" because it defeats the whole point. Tirion's own power and connection to the Light was forged through the faith and conviction he had in his own beliefs. You either follow your ideals to the bitter end or you don't even attempt to uphold them to begin with.
In other words, be either a Tirion or a Sylvanas. Don't be a fucking Garrosh.