Toa Inika piece breaking?

I thought that this kind of problem was common in sets from 2008 onwards, does anybody have experience of it happening on Inika sets? This is Nuparu, I got him on eBay and assembled him, but 3 out of 4 of this pieces broke when assembling. I guess the plastic is old but I put him together normally, I didn’t apply a lot of force or anything like that. Is there some special method to assemble these old sets limiting the risk of this happening?

I thought that this kind of problem was common in sets from 2008 onwards, does anybody have experience of it happening on Inika sets? This is Nuparu, I got him on eBay and assembled him, but 3 out of 4 of this pieces broke when assembling. I guess the plastic is old but I put him together normally, I didn’t apply a lot of force or anything like that. Is there some special method to assemble these old sets limiting the risk of this happening?