Judo specialists really have to specialize and work on what works in judo. Which in sambo offensively can sometimes work wonders, but not defensively (leg takedowns, leg submissions, etc).
Some Sambo teams like France, Spain, Germany, Italy, Netherlands, have a great deal of "pro" judoka in their teams and constantly and soundly get beaten by Russian, Ukrainian, Georgian, etc sambists in Sambo, and they also lose to some countries they would not lose to in judo.
This development means specialization, and can mean sometimes over specialization. They lose usually because of poor leg defense, different grip fighting principles, leg submissions.
If they fix and adjust all of this in their judo they can hardly be called pure judoka... Because they are now doing Sambo or "very old judo". Physical tools of Sambo and judo are very similar, but not the same. Much less so for combat Sambo.