What type of system? How many sites are you scanning?
The general answer is no, it has no bearing on scan speed. In fact, when you scan a trunked system that uses a dedicated control channel (e.g. P25, Motorola 3600, MOTOTRBO Connect Plus, etc.) there really is no such animal as "scan speed". The scanner dwells on the control channel waiting for voice call grants, then switches to the corresponding frequency to receive them. When complete, it switches back to the control channel and dwells until the next grant.
You can program 1 or 100 talkgroups, ID Scan or ID Search, and it's all the same. The scanner is processing the TGID's it sees in the control channel stream, it is not continuously scanning through a bunch of talkgroups hoping to find one that is active.
Of course scan speed can be affected based on the number of systems and sites being scanned. If you scan 2 or more sites, even of the same system, then it will take the scanner 2 or so seconds to jump between sites, assuming you don't tweak anything like the hold time settings per-site.