S7-200 networking

Hi fellas,
I currently have an existing network as shown in my attached drawing. (Items 1 and 2)
I am looking to add another panel (Item 3)


The existing network is configured as follows. Both HMI devices communicate solely with the S7-224 PLC. The S7-224 uses the S7-222 (In panel 1) as remote I/O. I configured the comms using the wizard, basically it reads the input byte from the 222 does the logic in the 224 and writes a byte of memory directly back into the output byte of the 222. There is no real process involved, it's gathering data and relaying information via LED's on the panel.

I am now looking to add panel 3 and am wondering how best to approach this. I will require info from the S7-222 in panel 1.

The way I see it, I have 2 ways of doing this:

a) I could program the new 222 unit to read directly from the existing 222, could this cause a problem?

b) Or should I use the S7-224 in panel 2 to read the info from panel 1 then write it to panel 3.

Option b would have the disadvatage that if the S7-224 was off then all my comms are screwed. But has the advantage that all the comms are being done from the one place and therefore should be more reliable.

I am probably worrying about nothing, but would appreciate any advice offered.

Thanks in advance.

As you have already stated, the 224 is the Master.
I'd plug in the new 222 to be a remote I/O similar,
setup to the existing 222.
Kind of looks cleaner as a system having one master
and 2 slaves (Remote I/O units).
Just the way I see things anyways!