No problem running both at the same time. Ours run continuously all day on most days, but, we're cooling 40 foot and 4 slides.
On a side note, we have 13.5k non-ducted units on our anchor winch cabs offshore. They run 24/7, 365. Most don't even have filters in them. These are some of the most abused neglected RV AC's I've been around. I've got some that have been running for 2 years now, non-stop. In the winter, they're non-stop with the heat strip. I thought it was cool to have them out here as I can use them as test dummies at somebody else's expense.
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.