Question. Do you also plan to upgrade shifters? If not, why not? My view is, shifters are at least as important, maybe more so than are derailleurs.

Second, why do you want to switch from mountain to road groups? Wouldn't it make more sense to upgrade to Deore rather than Tiagra or Sora?

Edit. Maybe others will chime in, but I don't think you can put road derailleurs on your Scott without also switching the rear cassette.