A consulting Arborist????? or do you mean RCA? big difference! basically a certified arborist will be just fine as long as he/she is knowledgeable in regards to the issues at hand, you wouldnt want an Arborist from PA to consult on a palm issue in FL..........however some are very well versed in species from different regions.
I know alot of Arborists who think they are consultants.............just because one calls themselves such does`nt mean they are!! if they are an Arborist & are engaged in consulting for court purposes/insurance claims, etc.. & charge a fee??? they better show they have some form of study in Law & if they dont...........I wouldnt hire them!!!!
consulting on PHC & tree related issues are one thing for a CA thats not registered, but anything dealing with court, suits, torts, civil/criminal issues & other is a whole other matter & you will want a RCA or a CA w/law background!
good luck,
LXT.............