Many Union players were recruited on their kicking skills both from hand and from conversions/penalties.In years gone by kicking duels between RL full backs were commonplace (I'd imagine pretty similar to what we call aimpess hoofing downfield in modern day union). I'm not old enough to know how structured the kicking duels were -))The best place kickers in League 'generally' came from union backgrounds - apart from Neil Fox, the main RL records for points (usually from conversions and penalties) were union players - Sullivan, Watkins, Lewis Jones etc.In the main, the top RL try scorers were from RL backgrounds - Bevan, Ellaby, Southward, Hanley, etc. Some will say what about Boston and Offiah from union? But to counteract, their union first class careers were so limited to hardly claim it was their union attacking skills that they brought to League. They were just about fresh out of school. They had raw talent, speed and in Bostons case raw power. The League coaches developed this. They didn't bring those skills from union.
You miss a vital point about Boston and Offiah. Both black and forth at reason alone they did not play for their country - in Union. Of course in RL they were welcome with open arms into the int. team withine five minutes.