Sorry dude but this is not a competitive ork list.
Where are your boyz? I really can’t say this enough: an ork army must be filled to the brim with boyz. Here are your options 60 boyz in wagons, 72 boyz in trucks or 120-180 boyz on foot(upgrading nobz where applicable.)
Nobz are in no shape or form a reasonable substitute for boyz, they are much more expensive, their stat line just isn't worht the cost, and they fill the same role as normal boyz. Any why the ‘eavy armor? You have FNP. Just move one of the combi weapons to the ‘eavy armor guy and you still have all unique units
Your loota groups are too big, at their size you'll kill stuff but you'll also be wasting alot of shots.
Boarding planks and deff rolas are somewhat redundant and deff rolas full the roll much much better.
Like sullen said don't mix fast and slow elements in a list, no walkers and wagons at the same time.