Well... they should both work, even at the default config, with a little lag, perhaps...
Please try to post more details about your computer (Procesor type, amount of ram memory, videocard and the like), and also open your dosbox.conf in notepad, copy it to the clipboard and paste it in a post, so we can have a good look at it 😉

I'm running damn near the same comp, and here's what I had to do.

From start...

I mounted my directory where Seasons was located, then accessed it (in my case mount c "C:\oldgames", then "C:", then "cd Sakura" as input commands)

Finally, and here's the kicker. you need to run the PMDIBM.COM file in DOS first, so the next input should be just that.

Then run SAKU-FM and you should be gold. 😀

I've not played Three Sisters, so no help there, sorry. 😢