Even if and Despite , question on paraphrasing

Hi, I am a Korean Teacher, teaching English to high school students. Prior to expressing this topic I want to discuss, I am sorry that my English might be a bit difficult to read.

While I was making some questions for our final exam, I bumped into a dilemma, so now I ask you native speakers questions on this.

The original version of the sentence was,

Meanwhile the Neanderthals, who didn't travel as far, never fostered a spatial skill set; despite being sophisticated hunters, well adapted to the cold and able to see in the dark, they went extinct.

and I paraphrased the subordinate sentence starting with 'despite' to this one,

'even if' they were sophisticated hunters,

and I underlined 'were' in order to test whether they know 'were' is a grammatical form.

But someone challenged this question as not righteous, because even if is not used to convey the concession in this context.

is the sentence I paraphrased not grammatical or natural?

thank you for your responding in advance.