If the inverters are perfectly in phase you might get away with it. If slightly out of phase one or both might shut down, sensing an overload. If totally out of phase it will be like a dead short.
Two inverters in parallel on the input side, 12 Volt, are not an issue.
Like a famous character in the movies said. "Do you feel lucky".
There are several EE's here that might want to confirm this and perhaps elaborate.
"A wise man can change his mind. A fool never will."
"Sometimes you're the dog, sometimes you're the tree"
2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan