My suggestion for fleet upgrade/downgrades:
30 - SLBP side full DD (536 is going to another operator)
99 - Full DD fleet with 23 buses, no SD buses
111 - Add 1 AP DD
145 - 7 DDs, 16 SDs, 145 is spammed with too many buses to the
point where bunching is extremely common
198 - Full DD fleet for this high demand service, BNL queues can
hit above 40 pax during PM peak (though there is 157 and 187
complimenting 198, 198 seems to be the preferred choice due to its
frequency and majority DD fleet)
242 - doing well with current fleet but can exchange 2 SD for 1
DD, high bunching tendancy near the looping point during peak
243G/W - B10BLEs and DDs only, convert 2 WAB SD to 1 DD, 243 is
overly spammed with SD buses
256 - Full SD fleet, add 1 bus to boost peak hour frequency