I will just use the nicknames here, easier to type
I have both Rat Tail and Peanut cacti, they do have similar looking blooms, but the growth of the plant is different. Rat Tail stems grows upright then pendent, while peanut cacti grows more in a cluster/mound of stems upright then slightly leans/ angled but not all the way down.
Also the buds of Rat Tail it seems to extend further from the main plant as it tries to get more light before the buds open up. During spring some tips of Rat Tail also has that pinkish tips, somehow reminds me of a rodent's pinkish nose.
The color of the flowers for rat tail is red as in this case, there are some with pink color. Peanut cacti buds/flowers remains closer to the plant, and the tips do not go pinkish. Peanut cacti flowers are more red orange in color.
Here are photos of mine from last year when in bloom.
Rat tail cactus
The pinkish tips:
Peanut cactus:
