Is it necessary that we take initiation from a siddha guru and not a sadhaka-guru?

From Anand Zope.

I came in contact with one Gaudiya Sanyasi in Puri.In a discussion he said U should Take Initiation from Siddha Guru & not Sadhya Guru.I couldn’t understand explanation given by him.If it is possible can u please help me in this regard ?