> In addition, they were the ones that pushed heavily for a monoculture on potatoes and a few oats over a diverse agricultural landscape; which allowed the famine to get so widespread.

That doesn't mesh with what I've read. The English were generally derisive of the Irish's reliance on potatoes. But the Irish became reliant on potatoes because of the shrinking size of the average tenant farmer's allotment. Potatoes are labor intensive but produce a higher number of calories per area of land than others staple crops, especially on marginal land.