I have had two copies of the same camera body simultaneously eight times since I got serious about photography again back in 2009. The most recent time was from February to July in 2023 when I had two EOS R bodies. I sold them to get one EOS R6 body to have the in body image stabilization for use with non stabilized lenses.
Then, in May of this year, I picked up an R8 and ended up liking the smaller, lighter body with a bit more resolution so much I sold the R6. My plan was to stick with the R8 and three image stabilized prime lenses. Then Canon came out with the compact and weather sealed 28-70mm f/2.8 IS lens. A lens I couldn't resist and I'm very glad I acquired.
These four lenses and a single body do not an ideal kit make. There are several practical options for a second body. I even considered crop sensor bodies but I quickly ruled out mixing sensor sizes. The R6 Mark II is a better camera than the R8 but having just sold my R6 I didn't want to go that route. I would be constantly feeling the need to decide which to use with what and for what. And I don't need in body stabilization with these lenses.
So, I picked up a second R8 body. This second body will mostly stay paired with the 35mm f/1.8 IS STM lens. Occasionally, I will carry both bodies with the zoom lens on one and, depending on the situation, either the 24mm or 85mm lens on the other.
I have the extension grip on the first body to use with the heavier and larger lenses so I put Peak Design Anchor Links on the strap ends of my OP/TECH Dual Harness so I can avoid using the Black Rapid tripod mount system which doesn't work well with the extension grip as it attaches to the screw mount wheel of the grip which could loosen while in use.
I would very much like to maintain this kit for the next year or so only adding necessary replacements such as batteries, filters, memory cards, etc.
UPDATE: I have picked up a Lowepro Flipside 300AW III backpack to store most of the gear. I can also hike with this bag which weighs 112 pounds as currently constituted. The chargers, speedlites and batteries are in a Canon shoulder bag which does not get carried around. That bag, the dual harness, tripod and some smaller carry bags are organized in a foldable tote.