I would suggest, Peter was a very competent driver, especially long distance, but, not deserving (maybe) of the hero worship he attracts ![:rolleyes:](https://bb2.autosport.com/public/style_emoticons/default/rolleyes.gif)
Perhaps he was born ten years too late? By the time he got into his stride, Australian racing was really a bit 'provincial' and there didn't seem to be that steady stream of Antipodeans coming to Europe that we saw in the 60s. I guess Bruce's death and Black Jack's retirement had a lot to do with that - there was no longer a guaranteed 'home from home'. The end of the Tasman series must have been another factor.
Speaking as a Pom, I reckon Brock could probably have cut it in Europe in touring cars and maybe even in endurance racing, but I wouldn't put him up with the greats of endurance at the time - he was no Bell, Ickx or Wollek and I'm not sure he would even have aspired to that. He chose to (mostly) stay at home and be a big fish in a small pond and maybe you only have to look at the experiences of a few of his contemporaries who tried and failed in Europe to get an idea of why: Perkins, Walker, Schenken ...
Added to that, Brock didn't have the open-wheel experience which was then pretty much the accepted way to get to the top in Europe. You did FF/FV/FFrance, F3, F2 and then hopefully F1: some, like Elford, took a different route, but getting an F1 seat was the way to get yourself noticed - even by the sports car teams. That was the way Vern Schuppan did it, for one.