I believe that I must be the last gardener on the planet to realize that John Scheepers and Van Engelen are sister companies, but I offer this information for others of my unbaptized and unknowing ilk.
They tipped their hand this year, bulb emperors without clothes, because I received both catalogs by mail on the same day, a seeming coincidence that initially elicited my amusement at the acute timing of the two companies. That night, as I feverishly looked through the luscious, colored John Schleepers catalog for some desired lilies and alliums, and then through bland Van Engelen, I realized that both catalogs had the SAME OFFERINGS listed BY THE SAME EXACT ORDER! Always slow, and one to easily be fooled, I looked at the information for ordering and found both companies had the same exact address and phone number. Fool me for a decade, but never longer. I was somewhat chagrined to search the internet and discover that such a treasonous bit of advertising sleight-of-hand was certainly not an unheralded secret.
I have ordered from both over the past few years, and I was initially a little angry that some devious advertising executives had taken me in, but further investigation revealed that the Van Engelen website freely discloses that both companies had the same owner and the same offerings and it tells me the reason why I (and you) want BOTH catalogs; "John Scheepers offers flower bulbs in smaller units with significant volume price discounts while Van Engelen offers the flower bulb collection in larger, wholesale units with volume discount pricing." John Scheepers and Van Engelen were, in fact, both owned by the late Jan S. Ohms, as is John Scheepers Kitchen Garden Seeds. Ohms acquired Van Engelen in the 1970's and John Scheepers in 1991.
For my purposes, the well-illustrated John Scheepers catalog allows me to see and pick items by appearance, but after identifying my shopping list there, I turn to Van Engelen, which offers better pricing for both small (5 bulb) and large (>100 bulb) lots. Oddly, Van Engelen doesn't offer lots of 10 bulbs and other intermediate sizes, so for some items, John Scheepers is the better source. This year I've identified 14 items, 10 of which I'll purchase from Van Engelen, and the other four from John Scheepers. I still don't understand why the companies publish and mail me two separate catalogs, a duplicate expense that surely must be reflected in the price of the bulbs, but I recognize that the answer may be entirely logical but beyond me, tied up in some Federal red tape of bulb importing and wholesale laws of which I'm happy to remain ignorant. Or, it could be that the blue-blooded upper crust of bulb gardeners spurn the colored-flower pornography of John Scheepers and stick with the tasteful lists of Van Engelen. And I suppose that Van Engelen sounds more Dutch and authentic for a bulb source than John Scheepers. Regardless, if you've only been buying gluttonously large lots from Van Engelen, make sure you receive a John Scheepers catalog as well, if only to look at or drool on the photos of each item.
Note: I am not associated with either Van Engelen or John Scheepers, nor do I receive any favors from either firm beyond the services they provide their average customer.