SPDR S&P Euro Dividend Aristocrats vs SPDR S&P US Dividend Aristocrats

They track different indices: SPDR S&P Euro Dividend Aristocrats follows S&P Euro High Yield Dividend Aristocrats and SPDR S&P US Dividend Aristocrats follows S&P High Yield Dividend Aristocrats. They also differ in cost (0.30% vs 0.35% TER), replication (physical vs physical) and domicile (Irlanda vs Irlanda).

Nobody can know that: they track different indices, so their returns will diverge, and past index performance is not a prediction. What you can control today is the cost, the tax structure and whether the index actually covers what you want exposure to.

SPDR S&P Euro Dividend Aristocrats has the lower annual fee. Applying the same 7% gross return to both with €300/month, that fee gap alone is worth about €916 after 20 years — that part is arithmetic, not a forecast.

Both are distributing, so on this point there is no difference between them.

Yes. Unlike two funds tracking the identical index, these give you genuinely different exposure, so holding both is not automatically redundant — just be aware you may end up overlapping on the largest companies and doubling your rebalancing work.