Wired Intelligent Edge

I have 2x HP3800 stack with stacking cables and configured as stack and 3 VLANs (1,2 and 3)

Planning to get 3x HP 3800 for my other office and need to connect back via SFP fibre transiver.  Can i have these 3 switches join to the existing stack? will there be any distruption to my existing switches that i need to take care of?

The 3800 stscking is done using the stack module installed in the rear of the switch.

The cables available for stacking are maximum 3m long.