I don't know if he is underrated by a majority of people, but I feel like I underrated him and have recently began to see him in a different light and I think if he went full on against someone that he'd own.. except against very exceptional people like maybe the Kage, but Obito, as the Juubi's Jin is ridiculously powerful... lol so it does kinda suck that we see him fighting Obito cuz he's even stronger than Hashi right now.. as it is, the only hits against obito have come because of Tobi/ftg--yes i'm aware minato helped one time but the second time was just him and naruto. using that little FTG trick with the clones is badass, switching places like that, LoL, and it's cool that 2 ftg users can do it together instead of using clones, lol. i think so at least
it's hard for me to fathom such a strong suiton user / ftg user (and edo tensei.. but i'm not sure how much he used that jutsu) dying against 20 people.. the only ways I see that happening are 1) plot or 2) it was 20 ridiculously strong people or 3) maybe he can't use ftg it as well as Minato, which is possible because I haven't seen him use the shuriken with the markings on them.. without being able to mark people he can't fly around as swiftly and accurately and so minato makes up for that with the shuriken but Tobirama doesn't seem to do that.. but if he used Edo Tensei he would never have lost, lol, unless he Edo'd some weak ass fools.. LoL.
but number 2) has some merit as well because Tobirama and his entire group were running from the pursuers.. you would think Tobirama and Kagami Uchiha and Hiruzen and Danzo as young men could have easily take 20 people but they were running for their lives.. the only reason to leave a decoy is to let the rest run away and live.. so it seems those 20 were no weaklings.. and Tobirama knew it was certain death.. so unless i'm reading too much into and they were running for a different reason..