Internet hits of Tam following Bene are in an Adverb-Adjective stack, with tam modifying the succeeding word, not the preceding bene
tam • adverbial deictic intensifier • tantum
why wouldn't "bene tam olet" work?
Adverbs are normally placed before the word to which they relate. In this sentence with two adverbs, tam relates to bene and bene relates to the verb olet.
why do I constantly get marked incorrect for different word order?
word order mean little in Latin
Word order is flexible but not free. And word order is meaningful. See, for example, Devine and Stephens' Pragmatics for Latin.