In the original post, he said, "Doing a larger Residential job in Vegas. The resident currently has a 400A MSP w/ 2, 200A Disconnects (going to their own 200A Panelboards)." Nothing about the 200A discos being service disconnects. If they are and what he said implies that, that's what I didn't get. If the MSP doesn't a 400A main breaker, that's obviously a different situation. He did say that the AHJ doesn't allow line side connections, though, and any connections on the line side of the discos (if they are service discos) are obviously line side connections. I work with an AHJ near here that has that policy, and the method of connection (tapping conductors or landing on busbars) is not the issue.