The amazing thing is that all 22 shrutis are connected to each other only by the most pleasant harmony relationships, namely, S:G1 (100:125) and S:P (100:150) ratios only, as shown below.
Topic 54: Selection of shrutis in various Ragas in Indian (Hindustani) Classical Music
between m1-r1 and m2-r2 There aren't perfect fifths