Regional hexagonal Tile rewriting grammars(RHTRG) are the recently introduced hexagonal picture generating devices which used a simple type of tiling called regional hexagonal tiling. This model is having isometric rules of derivation and more general than context-free Hexagonal array grammars (HAG) but incomparable with hexagonal tiling systems (HTS). In this paper we compare RHTRG with some parallel generating formalisms like Extended pure 2D hexagonal context-free grammars with regular control and hexagonal array token Petri net Structure with respect to generating capacity..