Dali Helicons and IKONs timbre matched?

I was wondering how closely timbre matched the Dali IKONs and Helicons are? Any listening experience / thoughts on this would be appreciated.

Am trying to determine if its feasible to use IKON On-Walls as sides and IKON 2s as rears in a 7.1 speaker system with Helicon 400s for Left and Right, and the Helicon C200 for Center.

I do think timbre matching is an important factor, so I would only consider IKONs or Helicons for the surrounds.