They may be on par but Madara fought Hashirama so may be he lost his eye sight early since Hashirama was whole other levelThey where equal based on MS.
Also Izuna seemed to have better controll over hes MS.
Since Madara spammed hes MS thus Madara was loosing hes eyesight.
Izuna gave/was taken hes eyes to Madara.
Madara became EMS user.
After this Izuna was out of the comparisson.
Since Izuna was blind after this.
For some reason I think , that both of them had Susanoo + something else.
But Perfect Susanoo is EMS technique only.
So Perfect susanoo originates from Izuna.
And Izuna did not fight with Hashirama since Madara always fought Hashirama since he knew Hashirama will defeat Izuna easily...
Hashirama and Madara were in the league of their own....... So I don't think Izuna was on par with Madara but might give him hard time......