Pairing 250 and 220 Expert Pro CIs...possible?

[musialsuspect]

I apologize if this is an incredibly naive question, but asking then listening is how we learn. (I've tried to locate a thread on my topic but have come up empty.)

I bought an 220 Expert Pro CI a year ago when what I really wanted was the 250 Expert Pro CI. At the time, the 250 wasn't offered on the US website, and I thought there would be incompatibility with one from another region. (If I'd known this forum existed, I would have been able to do much better research before purchase!) Amazingly, one became available very soon after my original purchase. Now I have both.

I suppose I'll sell the 220. In the meantime, though, I'm wondering...is it possible to pair the 250 and 220 in a dual mono set up with the 250 as the master?

If it's possible, is it desirable?

Have any of you experimented with this on-the-surface mismatch?  

Thanks in advance for the education.