Do arbitrage and private-label sellers need different tools?

Yes, mostly. Arbitrage and wholesale live on price-history and sourcing tools — SellerAmp, Tactical Arbitrage, BuyBotPro — that answer "should I buy this unit right now?" Private label lives on demand-and-keyword research suites — Helium 10, Jungle Scout, SmartScout — that answer "what should I build and how do I rank it?" The overlap is a profit/accounting tool, which every model needs to know its true net margin. Buy for your model, not the influencer bundle.