I'm a bit surprised that tofu is ahead of beans, especially in the Planet Score, since it's kind of just further processed beans.
My best guess is that the non-determinate "beans" are an average or something like kidney beans, whereas tofu is specifically soy beans.
And well, Wikipedia tells me that soy beans kick ass:
Cultivation of soybeans has one of the lowest needs for land use (1.3 m² / 1000 kcal) and emits some of the lowest amounts of greenhouse gas emissions per gram of edible protein of any food (1.6 kg CO2 / 100 g protein).
Would probably need to e-mail them to ask for the actual data... 🥴