It can be done, but it would require som form of objective ranking system. Sort of a system where each meeting and heat result is weighted using som form av formulas depending on league/competition typ, riding position, opponents, heat score, meeting score. It would be very complicated and probably quite impractical.
You could say the same about Lindgren, Lambert (and MJJ IIRC). They (especially Lindgren) got chances to prove themselves but did not take it. However they improved and here we are with all three being really good in SGP.