I go the opposite way for deads personally to the more is more. We are all different. If that is his bench vs Dead I think he might qualify for some more is more too.
Get your form down on lock (take some videos look at them post them here). That will probably add 50 pounds to your dead right there.
But it should also fix your back issues.
For me the biggest issue with less is more is that means heavier weights usually and that leads to back tenderness in me. So hit some reps, build all those muscles that keep your back strong.
Sample Deadlift Workout to be performed every 3rd to 5th day:
Percentages based off of working weight
3-5 reps @25%-50%-75%-90%
3 sets of max reps @ Working weight (100%)
If you get 20+ reps in those 3 sets add 5% for next workout.
Start around 225-275.
and if your time line is 6 months to a year then do this for 5 months to 11 months.
You can test your 1RM as often as you want but ideally less than once a month.