Possibilities for 24v Solar charging of 12v batteries in series and parallel with different Ah capacities
Yes, that is perfectly reasonable, but also connect the 12V points across the two banks. So you have two banks connected in series, where each bank is a 200Ah and 150Ah in parallel. Also, if there is a chance things may get out of balance, you can put a protection circuit across each 12 bank (like ~16V zeners).

EDITED: Thought I better change the 15V suggestion to 16V. Just make sure a standard 14.4 volt charge (per 12V bank) doesn't cause notable zener current.