Indeed. These cars already with OE alignment and square tire sizing are already understeer biased which many doing performance/track driving dislike and tune out for closer to neutral grip balance. It seems very wrong to make it even worse by going staggered.
Just get 225 all around, this way you'll also retain ability to rotate tires to even out wear, will still be able to use spacesaver tire (which on cars with LSD like ours, requires in case of punctured rear for same tire to be fitted (normally - front) to rear, and spacesaver used on front), will simplify finding/buying tires, especially if partial replacement. There is absolutely no practical reason to go staggered except if one is nutjob with goal to fit widest tires possible without rubbing (a bit wider possible in rear) at expense of anything else. 225 are not that wide to need that. If wheels are also staggered width that adds inconvenience to sell them off later in future.
My friend, whose car had staggered tire sizing stock, hated several inconveniences from dealing with that. Now why change it, when you have from many viewpoints easiest to live with square sizing stock?
P.S. For less tail happy car i suggest two things. Better grippier tire model then simply going wider, and also add in alignment a bit more rear toe-in (well evened out at that).