Instead of trying to hold on to lands that are in terms of ratio, disproportionately larger to the number of cadres available to help retain it, Prabhakaran seems to have opted to define a viable, strategic area and defend it with an optimum force
True.
But with that choice, VP has also limited the maneuvering space for his cadres. That is why artillery option (not motar) is not viable in defending Kili at this close quarters.
He may have opted this to lengthen the struggle after realising that SLA and MR outfoxed him and that he has already lost the battle in theory.
Concentrating all his cadres in to kili surrounded by hastily constructed earth bunds in my view will be deadly for LTTE. Sooner or later, SLA and SLAF will be able to take them out like 'Shooting fish in a barrel'.