In fbb's haste to complete a blog for yesterday, he forgot to explain.
How about train to Coventry, then bus? The X17 and the X18 both make the link via different routes. Stagecoach only provide a map of their routes from Hilton Hotel (wherever that might be) to Stratford.
There are lots of bus shelters right outside the station ...
Because they don't stop there. As the timetable says, you need to get to "Station Bridge",
fbb seems to remember a footpath via the car park offering a more direct link which may, or may not. be signposted.
Traveline? Usually takes you via the quicker but less accessible X18 via 2 minute run into the edge of the city centre.
As this blog reports at frequent intervals (yawn, same old same old), public transport is complex and far from easy.