hashi loses.
Frontline:
-itachi with ms(susanno, amateratsu, genjutsu)
-kisame with samahada large scale water attacks
-hidan could easily kill hashirama if he isnt taken out before blood drops
-nagato/pein with ct and all the other paths
Mid to long range:
-deidara with relentless bombings
-sasori with accurate one shot kill attacks along with black sand to help block attacks for the frontline
-konan with paper bombs
Kakuzu is the only one who could fight both close and mid/long range and with all of there attacks hashirama would eventually lose, no need to throw obito in this
if it gets really bad deidara kills everyone with c4, hashirama who cant see the tiny bombs wouldnt know what to do after the bomb pops and nothing happens. not to mention kakuzu would give them knowlegde on hashi's abilities (abilities that people might not know) so the akatsuki would get caught off guard