I think Robinson would have been as effective against anyone. Lomu was also an 'exception to the rule', size for the most part hinders speed and agility.
What I am saying has nothing to do with Eastmond.
Well considering that is exactly where the discussion started it has everything to do with eastmond.
Lomu was agile and fast so god knows where you think his size was a hindrance. *edit: just seen that's not what you were saying*
In some aspects they will beat smaller guys and in others the smallers guys will beat them. Benson Stanley is under 100kg and 6ft, still one of the best defenders in the world. Pocock is 6ft, Seymour 5ft11, Hooper 6ft. All flankers- Hooper and Seymour under 100kg. Also the bigger guy always beats the smaller ones ? You might want to look at the Australian backline. Toomua, Beale, Cooper, Ashley-Cooper, Lealiifano, Horne all under 100kg's.
I never said little guys couldn't be good defenders or beat big guys, but we're talking about defending and i just said they are less effective at stopping people on the tackle line (or at least that's what i'm getting at).
Regardless lets look at the guys you've mentioned,
Benson stanley is 98kg,
David Pocock is 104kg
Hooper is 97kg
Ashley-Cooper - 98kg
Lealiifano - 95kg
So yes under 100kg, well done (not that i ever said 100kg was the cut off) they are not giving up 20-30kg each time they take the field like eastmond is, the entire England midfield excluding easmtond is around the 106-110kg weight category, so someone like Stanley is giving up 6-7 kg not 20-30kg.
Beale is 90kg and a sh*t defender so hardly a great example.
Toomua is the odd one out because he's under 90kg and a destructive tackler in a way that Eastmond has never been - so you're not really doing your Eastmond is a effective defender argument any good here because Tommua shows how ti should be done - he's hardly the norm though and the NZ and Australian teams play a drift defence not a square on defence.
The question is does Eastmonds attacking skills outweigh his defensive deficiencies? I dunno, maybe.... but I'd say there is less of a differential between 36 or barretts defense and their creative skills than Eastmonds, i.e. they are more solid all round players than eastmond.
Look, we're getting bogged down in the detail, you can bring up individuals to try and pick holes in the arguments but wingers don't play and defend in midfield so Robinson is irrelevant to this discussion, Wilkinson was an anomaly and no one tackles like that anymore (or seldomly does).
Eastmond is a technically sound tackler, so is George Ford, but both of them are passive momentum tacklers which is not what England want. So unless Farrells going to change the whole defensive system just to accommodate Eastmond this is all redundant.