Even then:
Comparing word lengths only makes sense between languages of similar grammar, because differences in grammatical structure more often than not force you to add words to a sentence to keep the information inside.
This esp. when one of the languages is flexing (like PL) and the other not.
Example would be following piece of dialgue: Two people, one male the other female, are asked if they were out to do something specific (e.g. visit a museum).
While in PL the answers
"byłam" (I was) and "nie, odwiedzałem kumpla" (no I was visiting a pal) are sufficient to indicate who said what - because of gender suffixes to the verbs;
you have to write at least "I was - said $_female" to transmit the same amount of information.
Now keep the same in mind for adjectives, adverbs and differences between grammatical treatment of times...
While some languages do a lot of it by pre- and suffixes others require heaps of additional words for it.
German allows to save place with nouns - you can stick multiple to each other. so while you have to say "Office of Foobaric Affairs" in Polish, you simply have a german "Foobaroffice". Sounds like it would make things a lot shorter. Nevertheless, because Polish is flexing it allows for using less words in other cases. In fact it's a size difference of about 1/3rd shorter texts in Polish.
Then you have to keep in mind that not every word has a corresponding equivalent in every language.
There is no word for "toe" in PL (finger of foot is used)
There is no singular "parent" in DE (parentspart is used)
My points are as follows:
- Grammar matters more than raw word lenght
- An example like 'I can eat glass (...)' is by far not complex enough to allow reasonable sampling