All World Gayatri Pariwar

There are no restrictions on choosing more than one Guru . It all depends on the type and level of achievement sought for. Ram had Vashistha as his family Guru and Vishwamitra for learning of martial and other branches of knowledge. Dattatreya is known for having twenty four Guru s. Durvasa was family- Guru of Krishna and Brahaspati was his Guru in respect of learning the specific branches of knowledge. 

In schools, with the change in class, teachers also change. Village Purohit, Teerth Purohit, Family Purohit, Dikcha Purohit, Sadhana Purohit are all different. They do not contradict but supplement each other.