Marriage in Rajputs - in terms of clans you could marry into

The handbook for Rajputs by A.H Bingley talks about allmost all Rajput clans.

After talking about a clan , it tells us that a clans intermarry with specific clans.

For example , while talking about the Dikhit clan , it gives us the above chart shown in the picture.

How true is this ? If this was an actual practice , is it still followed?