If you specify a ServerOrder, you can have several servers that belong to that group. And each of those servers will be processed before any others, but they’ll be in random order inside that group. Here’s what a snapshot of the table could look like:

ServerName	ServerOrder
Server1	10
Server2	7
Server3	7
Server4	7
Server5	0

In the above table, Server1 will be processed first, and then Server2, 3, and 4 will be processed next, but in no particular order. But all the servers in group 7 will be processed before group 0.
Now let’s say that you want to process group 7 in a specific order. This is where ServerGroupOrder comes in. It specifies the order withing the ServerOrder group.

ServerName	ServerOrder	ServerGroupOrder
Server1	10	0
Server2	7	1
Server3	7	2
Server4	7	3
Server5	0	0

In the above table, everything stays the same except that group 7 will be processed in reverse order. Remember, this is weighted ordering, so the higher numbers will be processed first. So while in the first scenario above, group 7 is processed in the order of Server2, Server3, Server4. But in this scenario, where a ServerGroupOrder is defined, it’s processed in the order of Server4, Server3, Server2.
Most scenarios won’t need much ordering, but for large installations you may want to ensure that servers get processed in a specific order.