I have never used Surf Shark AV and can't offer personal experience. I use AV Comparatives to get information on what the best AV software is at the present time. Surf Shark does not appear on their list, so I would use one of the AVs tested by them. I have posted a link to their website for your review, if you are interested in checking their test results.
www.av-comparatives.org
PS: To more directly answer your question, if you install another antivirus product, Microsoft Defender Antivirus automatically disables itself and is indicated as such in the Windows Security app.