Just about every big brand food on the market uses Lucerne (Alfalfa). Cavy Cuisine which boasts of not doing has higher calcium than others that do.
I think a lot of rubbish is written about pellets. Dry food should only be a tiny part of their diet anyway.
I've kept guinea pigs all my life and a few years back I took onboard all the info you read on forums like this and swopped from Muesli food to Cavy Cuisine (and Kleenmama which cost me a fortune to import), plenty of hay of course and tried to balance the veggies as mentioned all over the internet to get correct ratios etc.
From that era I got the only two bladder stone pigs I've ever had.
So I don't take a lot of notice of food advice online any more.
I feed a muesli food, loads of hay, loads of vegetables, including the now disdained carrots. No more bladder stones.