You're in the ballpark. The spacers you're discussing are a bit odd in size (most bikes come w/ 1cm or 5mm spacers) but if those are what you have already then it sounds fine. If you plan on reselling the bike in the future maybe go with 3-and-change cm of spacers vs. 2-and change. Just put the remaining spacer above the stem if needed.

You're not in this situation but 4cm+ of spacers becomes unsafe for non-steel steerer tubes. Bad things can also happen if you're running a lightweight carbon steerer tube w/ no spacers, but again, not your situation.