ColumbiaMen's Fast Trek 2 Full Zip Fleece Full Zip Fleece Jacket (pack of 1)

Can this be zipped in to Columbia interchange jacket (3-in1)?

What is the diff size xl and size fr: xl ?

Do you need to purchase the next size up as indicated in the size chart ie xxl for uk xl 44" chest

this roomy or more of a slim fit, snug maybe?