Let's take an apparently difficult word like JAZZY:
- irAte - 117 words left
- clons - 15 words left
- dumpY - only 1 word left
- JAZZY
You don't have to wait until the 5th guess to realize the word has J and Z in it. Once the most common letters are eliminated, the range of choices reduces rapidly.
Let's take PENAL and PANEL (same letters):
- irAtE - 55 words left
- cLoNs - 5 words left
- dumPy - 2 words left
- PENAL or PANEL - 1 word left (or none)
- PANEL or PENAL
or ALERT, ALTER, and LATER (same letters):
- iRATE - 14 words left
- cLons - 2 words left
- ALERT or ALTER - 1 word left (or none)
- ALTER or ALERT
- iRATE - 14 words left
- cLons - 1 word left
- LATER
MAMMA:
- irAte - 117 words left
- clons - 15 words left
- duMpy - 2 words left
- bighA - 1 word left (although it would be smarter to use either MAMMA or GAMMA)
- MAMMA
I haven't tried them all but there must not be a lot that don't work. One I found that would be tricky is LOLLY - 2 words left for the 6th guess, LOLLY and JOLLY - but it is not on the WORDLE list (JOLLY is though).