Does size matter more than cost? AUM vs TER

Hey folks, Relatively simple question here but more research I've done the less sure I am. I'm increasing my exposure to Emerging Markets EM, and was settled on AEME on Paris exchange (€) until I found PRAM on XETR. AEME: Amundi Core MSCI EM, AUM: 6.64B, TER: 0.18 PRAM: Amundi Prime EM, AUM: 140.48M, TER: 0.1 I was always under the impression that lowest TER is most important determinant over long-term returns, but further reading and light research with Chat highlighted that a low AUM could incur significant costs from spread, and a initial calculation from chat indicated greater savings over time with PRAM than AEME. What are your thoughts on this? Which would you recommend, or a different EM ETF? Context: 32M, new European investor, portofolio around 60:40 ETFs:individual stocks, high risk tolerance, stable income and low mortgage. Will eventually drift to higher ETFs, less stocks, more bonds & commodities. Plan to invest €750/monthly, initially getting ETFs to desired proportion then balancing with selected stocks. Roughly 30k already invested. In terms of the EM ETF I would plan to start off with €500 and invest a further 100 monthly, long term vision 10+ years. I was planning to change from AEME to PRAM but calculations with an LLM suggested that spread fees would be greater than TER over time..? Supporting ETFs: 30-40%: WEBN AMUNDI Prime All Country World, 3.4B, 0.07% 10%: LYP6 Amundi Core STOXX Europe 600, 14.3B, 0.07% 5-10%: EM (?) Also, I've seen so many conflicting opinions, is it a bad idea to have 3 Amundi ETFs as a European investor or is it more safe than the hype of closures I see online? Thanks!