It depends on the difference in water content that you are talking about between the parts of the composite and whether they both independently meet stablity thresholds.
If you are saying can I mix a 17.5% with a 19.5% at 50/50 and get a stable 18.5% water content honey then the answer is regrettably 'no' not without active intervention - see 'UNLESS' below.
From a microbiological stability view point the answer is 'no' because the stability of the honey relies on water activity rather than the 'water content'. Water activity (Aw) is a measure of free water, in honey - that is water that is not bound to protein or within complex carbohydrate structures.
Since, yeasts are spread evenly through the honey the Aw at a micro level will dictate whether you get local 'pockets' of fermentation with associated acidification and gas production within the honey. Mixing will only give a standardisation of water content (not Aw) at a macro level. At a micro level the Aw of the original honey will likely still dictate stability and variation within the honey - UNLESS - you are actively shear mixing and pasteurising such that you re-distribute bound and free water evenly. Even then you'd need to validate becuse there is not a straight line relationship between Aw and water %.
Hope that helps. R