You can overdo it. A mix of tiers can cover both reach and trust, though too many types at once splinters the message and makes results hard to read. Pick a small combination that serves one clear goal, then judge each type on its own contribution before adding more.
Whether combining many influencer tiers and types strengthens a campaign or dilutes it.
The failure mode is not variety itself but losing the thread. A campaign that runs a big creator for reach, a few mid-tier voices for trust and some micro creators for niche depth can work well, because each type has a job. It breaks down when the roster grows without a reason and the message drifts between them, which also makes results impossible to attribute. Decide the goal first, then add only the types that serve it and measure each on its own. Choosing well matters more than choosing many. Flinque lets you filter and compare creators across tiers so the mix is deliberate rather than scattered, free at /find-influencers/.