There are untold numbers of RTs operating in the Expanse and various Dynasties have different measures of success. Some manage to get strong and slowly decline only to re-surge recently while others just decline. Others yet manage to stay as middling RT Dynasties.
I'm concerned with the declining ones. Given that the Imperium is more or less a feudal society that means there is hierarchy. While all RTs are "equals" some are just more equal then others. For example, Armelan* whose House is in deep decline, wouldn't have the same pull as say Whitescale. (*PG 24 of LotE)
Could Whitescale hire Armelan to work under him? Maybe even force the arrangement if he bested her in combat? Apart from the obvious pride issues, do you think a RT House would get desperate enough to essentially make themselves a vassal to a larger more powerful RT House?
Which brings me to this stray thought. Lets assume Whitescale kills Armelan in a fight. She's the last of her line. What happens to the Warrant? Does Whitescale get it by right of combat? Eat it to gain its powers? Give it to a cousin founding a cadet branch of the Whitescale Dynasty? Which brings us back to would that cadet branch be essentially a vassal to the main branch?