Wiring a GE smart switch in a box with 2 light switches sharing a neutral wire and switches sharing a hot wire on same circuit
This is not as hard as it looks

We can tell from your photo that the far left cable provides the always-hot and neutral for the lighting branches on the left and center switches, which leave via the two middle cables, while the far right cable is for the 3-way circuit and thus needs to be left alone.  Furthermore, we can see the neutral bundle for the two outdoor light circuits in the back of the box, running left to right.

This means that putting both outdoor lights on the same smart-switch is easy.  The neutral bundle gets pulled out from the back of the box and the switch's neutral gets added to it, with a pigtail of appropriate gauge wire used to make the connection.  Likewise, the existing ground bundle is pigtailed to the ground screw on the switch, and another pigtail is run from that ground bundle to the ground screw on the 3-way switch to the right, as the grounding in this box appears to be improper.

Then, we can cut the wire that connected to both the left and center switches (on their lower screws in your photo) back to just before the first stripped section, strip an end, and connect it to the LINE terminal on the switch.  The two wires going off to the outdoor lights are then wirenutted to a pigtail that connects to the LOAD terminal on the switch.  Get a suitable faceplate (3-gang with a blank in one position, a decorator or toggle in the second, and a toggle opening in the third -- modular faceplates are also an option for this, or you could use a switch-filler in the existing faceplate if your new smart switch uses a toggle style handle), button it all back up, turn the breaker on, and enjoy your new smart switch!