company share save

hi i have been saving in my company share scheme for almost 6 years they match 3%salary.

Shares have to be held for 5 years before they can be sold Tax and NI free.

i currently have almost £3k available to sell tax free and this figure rises each month as more of the shares become eligible to be sold.

My thinking is holding large amount in a single company is risky and i could instead invest into my S&S ISA to diversify and spread/reduce my risk a little would this seem a sound strategy?

Company shares are in USD which makes then even more volatile with recent events around the globe.

Thoughts most welcome thanks