If they don't have any clue, just move on. It's hard enough to find a title company that DOES understand the process and is ALSO really good. You don't want them bumbling up your deals.
It's very understandable that title companies don't understand assignments and "outside the box" deals, as many are just part of the MLS/Realtor system where everything is done a certain way, day in and day out. It's also why so many realtors look at you like you have two heads when you suggest that you have off-market deals their investor buyers might be interested in. *sigh*
Ah, I forgot to mention, your best bet is to reach out to other wholesalers in the area, or even just go to REIA meetings and ask other investors (wholesalers or not) what title companies they like. If investors are using them, they are probably good at outside the box deals.