Some confusing lemmatization results

[chadananda]

Perhaps I'm misunderstanding lemmatization. Am I supposed to be getting these results?

this -> thi
saying -> sail
pleased -> pleas
went -> wend
this -> thi
they -> thei
haste -> hast
mary -> mari
saying -> sail

[Berkmann18]

I don't think those are correct either.
I also see confusing ones such as:

coding -> ding
code -> de
design -> sign
deployed -> deployed (not deploy?)