Several virus programs simultaneously?

In my Windows 11 I use the built-in Defender. In Acronis there is another virus/malware protection function. In Advanced SystemCare  there seem to be still another virus protection. My question is - should I do away with one or two of them or are they overlapping each other?

You can follow the Best Practices for Safe Computing - Prevention of Malware Infection.

Additionally, you can use ConfigureDefender by Andy Ful to strengthen Microsoft Defender Antivirus.

Setting the Protection Levels in ConfigureDefender to 'High' is a good baseline and recommended for most users.

The ConfigureDefender.exe file is the second option on the GitHub website that you should download, save to your desktop, and run.

You can also use uBlock Origin, uBlock Origin Lite (MV3), AdGuard MV3, or Malwarebytes Browser Guard to block ads, scripts, spam, and trackers.

However, I do NOT know which edition of Acronis you are using, which is essential information regarding what type of virus/malware/ransomware protection you use.

If you use Acronis Cyber Protect Home Office Essentials, it includes ransomware protection, which is NOT an Antivirus/Antimalware.

If you use Acronis Cyber Protect Home Office Advanced, it includes ransomware protection, identity protection, and virus/malware protection.

If you use Acronis Cyber Protect Home Office Premium, it includes ransomware protection, identity protection, and virus/malware protection.

However, I would recommend that you uninstall IObit Advanced SystemCare PRO because it is a Registry Cleaner, Driver Updater, and Optimization Tool.

Good luck!

You should not use more than one anti-virus with real-time protection simultaneously. In addition to causing conflicts it can slow down computer performance and cause other issues. I explain in more detail why most security vendors advise against doing this under the IMPORTANT NOTE in the first link (Choosing an Anti-Virus Program - Post #2) provided by midimusicman79.

 
Advanced SystemCare products offer a suite of system optimization, auto cleaning and system tune up tools plus secure privacy and malware protection (antivirus) depending on whether using the Free, Pro or Ultimate version. Optimization includes a deep registry cleaner that purports to improve performance, make repairs and Boost your PC's speed by up to 200%.
 
The optimization and performance improvement claims made by such software vendors are borderline scams. There is no statistical evidence to back such claims. Advertisements to do so are a marketing ploy intended to goad users into using an unnecessary and potential dangerous product. I would not trust any results such programs detect as problematic or needing repair nor recommend using the options to fix them. 
 
Please read Why you should not use Registry Cleaners and Optimization Tools (Post #7)
 
Also be sure to read Microsoft's support policy for the use of registry cleaning utilities in that topic...Microsoft does not support the use of registry cleaners.
 
In the past, AV Comparatives said this about registry cleaning software. 

Some "classic clean-up software" such as "Ccleaner" are classified as "Useless" in this database because the Windows registry does not need any maintenance except if you are victim of a malware infection and because tweaking the windows registery does not speed up a computer at all. It does not mean that Cleaner and similar tools are not good for sweeping your harddrive and help to keep your privacy. Registry cleaners have been become social engineering products (e.g. Iobit Advanced System Care, CCleaner, Wise Registry Cleaner, etc.) and paying for this particular function is just a waste of money.