Does the sizing appears correct?
You have 1132Wh/day of power usage. Your battery bank is about 5000Wh but only 50% usable so that's 2500Wh. So your battery can provide just over 2 days of power without any recharging.
You are planning 1400W of solar so it will take just under an hour (assuming the full 1400W) to replenish your daily usage. Many factors will reduce the actual solar you get on a given day. You will certainly have cloudy days in the winter where you will not get enough solar to recharge your batteries.
Over time you may decide you need more solar and/or more batteries so your system can make it through more than two days of poor solar conditions.
Does the wiring diagram seems correct?
I see two things I would change.
1 - Use bus bars to connect your parallel battery strings together. This will make it much easier to add a 3rd set of batteries in the future if needed and to make all of the connections simpler.
2 - 4 solar panels in parallel requires that each panel be fused. This is best done using a combiner box. More on this later.
Are the fuse size correct?
Your 800W 24V inverter can pull up to 800W / 24V / 85% efficiency = 40A.
Your SCC can output up to 50A.
That's all you have connected to the battery. So the choice of 250A fuses for each battery string seems very excessive. And given your choice of 4AWG wire for the batteries, a 250A fuse is far too big for the wire. A fuse is meant to protect the wire so it is critical that the fuse size must not be too big for the wire. The largest fuse you should use on 4AWG wire is 150A.
For the inverter and its 40A load I would suggest a 50A fuse.
For the SCC and its 50A load I would suggest a 65A fuse. You probably won't be able to find a 65A fuse. 70A would be fine. 60A will probably work too.
Each battery string really only needs a 70A fuse for your planned setup. But I would use a 150A fuse with the 4AWG wire. This allows you to use a larger inverter if needed in the future.
Are the cable size correct?
The choice of 4AWG wire for the batteries is plenty big enough with the 800W inverter and 50A SCC. That choice of wire will actually let you grow up to about a 1600W inverter if ever needed.
For the 50A SCC you really should use 6AWG. The choice of 8AWG is too small.
For the 40A inverter the choice of 8AWG is marginal if you will regularly run it at the full 800W. 6AWG would be a better choice.
You don't mention what size wire you will run from the solar panels to the SCC. The size will depend on your final solar panel arrangement, the current of each panel, and the distance from the panels to the SCC.
Why 2 different sized solar panels? I would suggest just using 4 of the same wattage. 4 370W would be a better choice. You will be slightly over paneled with a 50A SCC. A 60A would allow you to take full advantage of the 1480W but the 50A will still work. I also strongly suggest arranging the 4 panels in 2S2P instead of 4P unless you have a lot of shading issues. 2S2P will eliminate the need for a combiner box and the extra fuses. It will also allow for smaller wire from the panels to the SCC. And you would only need 1 pair of Y connectors instead of 3 pairs.
If you do go with a 60A SCC then you will want 6AWG with a 75A fuse.
You should play around with Victron's MPPT calculator. You can enter your final panel configuration and it will show you the best choice of MPPT:
MPPT Calculator - Victron Energy
www.victronenergy.com
I can't be sure but your choice of an 800W inverter might be too small. Anything with a motor will have a big startup surge that can easily be more than double the running wattage. So your 450W vacuum may surge close to 1000W on startup. The Phoenix 800W inverter may be able to handle that surge. I would try to find someone with more experience with such use to confirm that the 800W inverter will handle your uses.
Since you are planning on a Cerbo GX then you might want to look at adding the associated touch screen display. If you do that then you can use the Victron SmartShunt instead of the BMV-702.
