Before revision:  In the present work, we present this key question: given a particular number of ancestors at each generation, how many different hypothetical trees can be constructed? Building upon our previous works, we propose an approach to estimate this number. Given that this number is quite large, we also address the non-trivial issue of tree representation .
After revision:  In previous works \mbox{%DIFAUXCMD PhysRevE.92.052132, PhysRevE.90.022125, JARNE20191 .