The question is between…
Resort monorail to TTC, TTC monorail to Epcot
OR
Walk past Poly to TTC, TTC monorail to Epcot
OR (technically)
Walk (or resort monorail, or boat) to MK, express monorail to TTC, TTC monorail to Epcot
Personally, if during “peak” travel times, I’d walk to TTC because the unloading and loading of passengers at the various monorail stops on the resort loop always seems to take forever. I can walk to TTC faster. However, at off-peak times when not as many passengers are getting on and off at the hotels, the resort monorail is easier than walking, especially if it’s hot out.
I think that third option is what was throwing you during your googling. There is an express monorail at MK, but it only goes to the TTC (directly, without stopping at any hotels) where you would then transfer to the Epcot monorail. There’s not much point in trying to head to Epcot by way of MK, since the time taken to transfer between monorails, etc. there would negate any time savings from being on the express and thus not making the various stops of the resort loop monorail.