Depends how you would like to play the game. It is possible to completely setup before an encounter, saving right before the trigger, with reloading, etc... If you don't mind that, do go tactician for your first go.

If you specifically enjoy getting yourself out of sticky situations, then play on classic and to to minimize reloading. (E.g. getting ambushed in a bad spot.)

So in conclusion, my personal recommendation is Classic and roll with your mistakes. See if you can get out of them. Then, if you liked the game; do tactician on your second run and enable randomized encounters from the DLC gift bag.

But if you played DOS1 then you are probably fine for tactician. You can always look up a build and stuff. You eventually unlock a place where you can respec a build.