Rager and Garetz both pre-dated Tinseth.
Tinseth combined the two to a certain extent and added some additional algorithms based on observed results.
If you believe Tinseths logic (in particular the "big Knees factor) which I do then you will use Tinseth.
It matters nothing, zilch, nada so long as you use the same calculation each time.
Talk to some experienced beer evaluators/judges.
Given that the beer is sound and within reasonable style guidlines a good evaluator should be prety close on the FG and by some quick backthink get the SG within 10% and thus guess the ABV (each time with greater error), she or he will make a comment as to the hop malt balance but will unable to distinguish the IBU varience between Rager, Garetz and Tinseth.
Bitter a VB wort to 30 IBU, bitter a dextrinous wort to 30 IBU, two totally different sensations of bitterness.
Make your choice and use it. Thats simple.
K