There is a resolution.
The xx45 (to round to an easy figure) departures from SHR arrive at BHM to depart back at xx00.
Those arrive into SHR at xx08 to form the xx13 semi-fast (WLN, TFC, SFN CSL, WVH, BHM) services, arriving xx25 to form xx35 semi fasts back to SHR which then form xx45 departures back to BHM. Rinse, repeat.
In recent 196 training, these xx13 paths have been used.
xx denotes the hour- saves writing out every single hour when services regularly depart at the same time each hour (or thereabouts)
SHR is Shrewsbury (station)
WLN is Wellington
TFC is telford
SFN is shifnal
CSL is Codsall
WVH is Wolverhampton
BHM is Birmingham New Street
196 denotes a Class 196 DMU which is a train used along that particular line. Class 170s are also used. These are trains too.
DMU stands for Diesel Multiple Unit.