Wosel... i'm curious - can one person have TWO root Lamas? I thought that we only have a single root Guru who is the teacher who made the biggest impact on us?
I do not have an answer to your question from any text or reference, but by logic, perhaps I can offer an explanation.
The definition of root lama or Tsawai Lama is the lama under whom you learn the most, who is able to bring you furthest in your spiritual journey, your spiritual guide and spiritual friend.
To say that there can be only one root lama is too confining. Just as one's yidam can change over the course of one's life, according to what one's need is at the time, then logically so too can one have different root lamas for different periods of one's life.
Another way to look at a root lama is by different areas of practice. To have one root lama for say, sutra, and another for tantra, with each lama being supremely qualified in their special area of expertise, perhaps this is another explanation for having more than one root lama.
Any comments would be appreciated