Good Post. For The Most Part Though, Everything Is Only Speculative; The Main Reason For That Being That Little If Anything Has Been Shown Concerning Either Hiruzen's Power In His Prime, Tobirama's Power, Or Even Hashirama's.
The Problem For Most People, In My Opinion, Is How To Successfully Weigh Each Of Their Reputations; Hiruzen Was Known As The 'God Of Shinobi', But Hashirama Is Forever Credited With His Control Over The Tailed Beasts And Defeating The Infamous Madara Uchiha, Who Possessed The Nine-Tails During Their Last Battle. Because Little Is Known Of Hiruzen's Power In His Youth, Everyone Jumps On The Hashirama Bandwagon.
In Terms Of Hiruzen And Minato, The Fans Of The Latter Are Most Likely Soo Focused On His Body Flicker Technique That They Don't Account For Everything Else The Battle May Hold. In Their Eyes, As Soon As Minato Marks Hiruzen With His Seal, It's Over, As Far As They're Concerned. Of Course, There's Much More To It Than That; And With Hiruzen Being Referred To As The 'God Of Shinobi' During His Time, I'm Sure He'd Figure Out A Way To Deal With It - Something Minato Fans Don't Care To Think About, Or Admit, For That Matter.
Regrettably, With Nothing Shown Of Hiruzen's Feats In The Past, While More Of Minato And A Bit Of Hashirama's Pasts Were Expanded Upon, Until Kishimoto Provides Us With A Flashback Of Hiruzen's Strength In His Prime, There Will Be An Endless Amount Of People Who View Hashirama/Minato As Being Greater Than Hiruzen, Power-Wise.