Looking up (retrospectively) journeys from Exeter Central to Melksham yesterday (as one does), I couldn't help noticing the advise to not bother with the train from Central down to St. David's but rather to walk it ... 15:24 departure on foot, 15:39 train from St David's to Westbury, 17:12 to Trowbridge, 8 minute walk from the station there to Fore Street and the ZigZag bus to Melksham.
More or less what I had actually done ... though I caught the train a couple of minutes earlier down the hill in Exeter; I note that cutting the maximum walk distance on traveline, though, switched me to a bus from Central to St. Davids - what HAVE they got against the train??
https://www.traveline.infoI wish traveline took account of overall price, ease of ticketing, and offered fallback data in case a connection misses.