Yes, you can put a 20mm strap on a 19mm lug width watch and a 22mm strap on a 21mm lug watch
Wide Adjustable Crossbody Strap 55 Inch Max Length 1.5
Watch Strap Size Guide
Leather Purse Strap Extender - 1/2 (half-inch) Wide - Nickel #13 Hook - Choose Color & Length, Replacement Purse Straps & Handbag Accessories - Leather, Chain & more
A How-to Guide for Choosing Your Cross Body Strap Length – Mautto
Shoulder Strap for Purses/bags Leather 30 Length /
Short Crossbody / Long Shoulder Strap - Choose Leather Color - 40 Length, 3/4 Wide, #16 Hooks, Replacement Purse Straps & Handbag Accessories - Leather, Chain & more
Wide Crossbody / Messenger Bag Strap 50 Inch Length 1.5
Watch Strap Sizing Explained [2022 Guide] • The Slender Wrist
Black Leather Strap for LV Speedy Noe Metis Trevi Etc