Does it make sense to try to force dry it?
Only you can answer this, since it's only your requirement that drives the decision to speed-dry versus just waiting for the wood to naturally season over a long time.
This piece, if dried whole, should be left for at least a year, unless you can put it somewhere unusually warm and consistently dry, ideally with good airflow too.
If yes then do smaller pieces dry with less cracking than larger ones?
If you don't seal the end grain, very much so.
If you do nothing to chunks of green wood cracks are virtually inevitable in most species, and they can be severe. However, given the exact requirement clarified in the Comments (small puukko style knives) it's possible that you could do nothing with a piece this size and still get numerous1 handle blanks from it.
I'm not talking about drying speed right now.
If you are intending to air-dry it's best practice to seal the end grain (see link below). This will maximise the yield2, giving you the most flexibility on what wood you can select from for each handle — choosing for grain, colour/figure — and so you have as much usable wood as possible for potential future uses.
If you split or saw the 'log' into wedges, these smaller pieces will air-dry substantially faster than the original piece of wood; note that it would be absolutely vital to seal the end grain if you do this because cracks in smaller pieces are more likely to intrude into wood you want to use. I've lost many handle blanks this way.
Additionally this would allow you to experiment if you'd like to, air-drying the majority of the pieces and trying out two of the fastest speed-drying methods — boiling and microwaving — which could potentially give useful handle blanks in half a day.
See A few notes on seasoning at the end of this Answer for some info on boiling handle blanks, and cautions about microwaving, as well as guidance on sealing the end grain with melted wax.
1 I'd say three for sure but as many as five might be possible.
2 If this chunk is long enough the yield could go up from 3-5 to as many as 10-12!