Yes, it's sad that he was killed during the war. But tragedy doesn't give him more credit than he actually obtained. No way he was as dominant as Nadal, and tennis was puny a century ago.
Well actually he was more dominant than Nadal on clay. Nadal never had a 4 year unbeaten stretch winning 35 clay court tournaments during that time. Does that make Wilding better, no of course not. Nadal is far better than Wilding was (on clay) and has achieved far more on clay...but not more dominant over his rivals.