And if Taumalolo gets an opportunity he will start on a massive pay reduction.
Nope - at least, not if he stays on the active roster.
Given the difference in exchange rates and income tax, if he was to earn the US$450k NFL league minimum, it would give him roughly AU$425k after tax.
Let's say he's earning AU$720k/year on his current contract (he's not), that would work out about the same after tax (using current exchange rates). Then there's potentially additional money in terms of apparel/increased sponsorship deals (even if he fails and comes back to the NRL, as we've seen with Hayne) to be factored in.
Even dropping to the practice squad isn't too bad - the possible boost in other incomes (which could be a longer term thing) is one part, then you get about US$7k/week on the practice squad plus whatever you earned pro-rata for the season in the active roster, and if you leave at the end of the year you can head straight back into the NRL thanks to the timing of the seasons.
Anyway, can't see it happening. His blocking won't be near the standard required to play in the line (tight end), he's the wrong build for a back (maybe fullback, but now we're back to blocking issues)... maybe as an outside linebacker used pretty much exclusively for pass rush, given his combination of power and lateral movement. Maybe. Holmes profiles even worse - no chance at any position.