I think you have to be careful with reductive vs. oxidative and really define the meaning of what oxidative is or what style you are looking for. Wines made in a reductive, stainless steel environment can taste identical to wines made in a more oxidative, barrel aged environment - especially as they age. This can lead to a very reductive wine that has seen a lot of reserve wines or post-disgorgement aging tasting similar to a wine made in what would be defined as a more oxidative environment. Likewise, wines made in barrel, can still come across as reductive.
Krug really isn’t all that oxidative. The wine spends most of its life in a reductive environment. Put it in a lineup of other barrel aged or oxidative wines and it is a very quiet soul. There is a lot more that goes into the Krug style than the three months the wines spend in fairly old oak barrels.
Outside of the general statement of reductive vs. oxidative, I think you really need to define if you are looking for richness, bright fruit, spice, steely sharpness, creamines, etc…
For example, Vilmart is made in oak and the Coeur de Cuvee is made in a mix of new to 3 year old barrels. The wines do not come across as oxidative at all, but rather what I would classify as more reductive with spicy notes. Charles Heidsieck is reductive in style, but the wines can be quite rich and creamy. Pierre Peters is also more reductive in style, but with time or when you drink a wine of Rodolphe’s that has a good amount of reserves in it, you get something that is both rich, creamy, bright, fruity, and sharp.
Complicating things even more is that you need to look at how the winemaking is handled in terms of sulfur use especially at disgorgement. I’ve seen wines taste reductive in one environment and very oxidative in another based on the what I can only call mishandling at disgorgement. Low/No sulfur wines often don’t travel well internationally and that can lead to a wine tasting one way in Champagne and completely differently in North America.
Some classic producers who are on the purity side of things and reductive in style are: Piper-Heidsieck, Veuve Clicquot, Lilbert, Pierre Peters, Lancelot-Pienne, Laurent-Perrier, Billecart-Salmon, Guiborat, Gosset, and Ruinart.
On the richer, but still reductive side to me would be Charles Heidsieck, Dom Perignon, Taittinger, Roederer, A Margaine, Hure, Etienne Calsac, Vilmart, Hebrart, Geoffroy.
There are lots, lots more, but above is what popped to mind first.