5's Pro for Back Assistance

I would like to run 5’s pro +fsl with pendlay rows for back assistance. Any reason not to?

I’ve tried those rows with various schemes and still can decide what works best. I’ve tried just a generic 3x10, 5’s pro, SST, and now I’m trying it with normal 531.

I have tried this with bent over rows - not sure what Pendlay rows are but if they are a row done with a barbell, and bent over, they are a bent over row.

I wouldn’t recommend it due to form going to shit when weight becomes much too heavy.

Back isn’t a movement, where is this assistance fitting in your program? After deads? Every workout? etc.

I guess I meant accessory instead of assistance.