@SethsVan
Move your negative to the bottom battery for better balance.
It is good practice to connect an inverter direct to the battery using the shortest and thickest cables possible especially if the intention is to use it near max capacity (not really recommended at 12v other than very briefly).
Your DC breaker for the B2B is rated too high.
Read the manual for the mppt controllers some are slightly more efficient at lower input voltages so serial isn't always best practice plus in parallel you will also get improved shade resilience.
Consider the Renogy DCC50S instead of the 40A Rover and DC to DC, the DCC50s also has the important benefit of two way (chassis) battery charging.
the 60A Rover is an expensive choice for only 600w of input
The Renogy Rover 40A controllers are best configured using user settings for Lithium batteries as they have a bug that means they never come out of bulk so batteries ae being hit with excess voltage for effectively ever, not good!
I do not know if the 60A unit has the same problem.
You will need to buy BT dongles for each unit to monitor them via the truly dire DC home app, imho it can actually work out cheaper to buy the top quality Victron Smart Solar controllers instead
The batteries do not have BMS monitoring which can be useful nor heating which is essential to be able charge at below 0C
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