Can I reduce the icon size on home screen iPad Air IOS 12.5.5...?

I have a 'spare' old iPad Air I've has since about 2014 (MD787B/A) running IOS 12.5.5 that I use for hiking, camping etc, as it doesn't matter much if it gets smashed. Compared to my iPad Pro, the (normal, unzoomed) icons on the home screen are HUMUNGOUS - is there any way to reduce them in 12.5.5, or am I stuck with the limitations of what is a pretty ancient iPad / OS?

Thanks in advance!