Nicely pointed out the event of Guru Vishwamitra saving Lakshman. Somewhat this show always reminds me about the guru-shishya relation. Now I can understand why drona (though he was not completely right) was too partial towards arjun, its the charm of the student which makes the guru select them as an ideal student.
Whatever path Ram went through (except for single marriage), he made Arjun to explore the path in his way. Why Krishna did not have such a powerful guru like Vasishta or vishwamitra?