Dividing irregular area

I am trying to divide this irregular area to different lots to generate different scenarios in order to calculate the best feasible option, but after defining the surface and using divide domain 2 and isotrem the fractions happen on a regular surface generated from the irregular one, which doesn`t help me in dividing the area to equal lots.

is there another way to divide irregular surfaces according to their area ?
Thanks in advance

You can look at that