Is the injury risk greater at 1b than 3b? I have no idea.
The biggest risk at both is runners. At 1b, they step on your foot or run into you. At third they often slide into you with spikes up, albeit less often.
Sure DH is less. But in 2-3 weeks, there’s a good chance a Toro/Gonzalez platoon fails to dazzle, to put it mildly.
Having all those players rotate in and out of DH to stay fresh is no different than platooning utility players at 1b. Plus it ignores the real reason Cora “rests” players - to give the bench players occasional action instead of letting them atrophy on the pine.
DH is a position. Fill it properly. It’s not for days off for starters any more than the closer role should be for resting starting pitchers…