The phrase "strikingly large" is correct and can be used in written English.
You can use this phrase to emphasize the size of something. For example, "The eagle had a strikingly large wingspan."
The benefits of high performance for productivity are strikingly large.
Students took to the streets, often in strikingly large numbers, to demonstrate against postsecondary tuition increases.
A strikingly large number of caspase targets are involved in cell cycle regulation.
The completed work was strikingly large: five feet by nine and a half feet.
There are strikingly large differences in the performances of academy chains.
"The current account deficit is similarly not a result of funding a household credit boom, but nonetheless is strikingly large.
A strikingly large share of the party establishment, for example, has already come around to Medicare-for-all.
"Yes, she's a victim of abuse, but so was Tina Turner!" Her eyes, already strikingly large, widen in exasperation.
The General Social Survey shows the same, a strikingly large, rise among "nones" in the last couple of decades.
There are strikingly large numbers of people in attendance on senior officials, apparently attending but doing little else.
Researchers at the London School of Economics found that France has a strikingly large number of companies with 49 employees.
