I'm glad you're being cautious, since this topic is like an Iraqi minefield. :-/
Linotype does have an Arabic expert in the person of Nadine Chahine, but even her great sensitivity cannot always totally overcome customer expectations... and customers are rarely sensitive enough to this topic. What I'm getting at is, no matter what the marketing people might tell you the Arabic companions to those classic Latin designs are indeed too modern - they don't say the same thing the Latin is saying. This doesn't mean you have to go full-on conservative (which is likely to backfire, irrespective of any stylistic discord). The good thing is you're not designing an entire harmonious typeface! That's a supreme challenge. You only need to make a logo. Although I assume you do also need to set extended text in Arabic?
Most of all, the actual nature and intent of the corporation you're dealing with will determine what direction to take. You might not be at liberty to disclose too much specific information here, but if you could elaborate a bit that would help greatly.
hhp
