The phrase "a somewhat more difficult" is correct and usable in written English.
It can be used when comparing the difficulty level of something to another, indicating that it is slightly more challenging.
Example: "This problem is a somewhat more difficult version of the one we solved last week."
Alternatives: "a bit more challenging" or "slightly harder".
That, Mr. Markowitz acknowledged, was a somewhat more difficult proposition.
The 5,201 memorial competitors had to invent a new way to convey feelings of unspeakable grief -- a somewhat more difficult request.
That would be a "somewhat more difficult question," Ms. McDowell said, because the designers would be required to support a program that was against their own interests.
A somewhat more difficult goal is to track down the woman who cared for and really loved Enrique, saving his life and then getting him to the shelter where he now has this second chance.
A somewhat more difficult problem is to predict extreme chemotherapy sensitivity, including all breast cancers in the analysis.
A somewhat more difficult ethical conflict was said to occur when pregnant women were prepared to make choices to secure the health of the fetus or to improve fetal outcome that would most likely cause morbidity for themselves.
Getting themselves to the party, however, turns out to be a journey somewhat more difficult than that endured by the Greeks coming home from Troy.
Getting themselves to the party, however, turns out to be a journey somewhat more difficult than that endured by the Greeks coming home from Troy, and the friendship of Hill and Cera, who are inseparable, almost breaks up from the strain of it.
Patrick Reason became a well-known engraver, famed for his engraving of a kneeling female slave with chains hanging from her wrist accompanied by the inscription "Am I Not a Woman and a Sister?" Black writing is somewhat more difficult to identify.
A problem that gets only somewhat more difficult as the numbers get bigger is said to be solvable in polynomial time.
