"incomparable knowledge" is a valid term that can be used in written English.
You could use it to refer to a deep level of knowledge that is beyond comparison. For example, you could say: "He had an incomparable knowledge of the field, which set him apart from the rest of the employees."
His support, encouragement and incomparable musical knowledge will be sorely missed.
Her dignity and incomparable musical knowledge enriched the lives of her many students.
His incomparable musical knowledge and artistry that were his gifts to all of us will be profoundly missed by all.
Yet no one is better able to weigh in on what will help children succeed academically than educators, who have incomparable firsthand knowledge.
A comprehensive investigation of rainstorms and their consequent impacts on landscape evolution is geomorphologically important, but only scant information may be available on exceptional events, because parameters on synoptic conditions, rainstorm, landforms and hydrology for such events may be incomparable with previous knowledge.
While Mario's knowledge of art was incomparable, his philosophy on works of art and their treatment lives on through those he tutored and befriended.
God is conceived to be essentially different from everything material, the absolute opposite of any evil, free from any imperfection, omniscient, omnipotent, possessed of all positive qualities (such as knowledge, bliss, beauty, and truth), of incomparable majesty, the inner soul of all beings, and the ultimate goal of every religious effort.
Challenged in recent years by illnesses, neither his great sense of humor nor his incomparable talent for storytelling wavered, and his thirst for knowledge and new challenges flourished unabated.
He's had an incredible career for however many decades and just the experience, the wisdom, the knowledge that this guy has is just incomparable to anybody else that I've ever gotten to work with.
The incomparable Ukrainian coverage by Sergei Loiko and Carol Williams takes guts, game – and a career's worth of knowledge of the region.
