Mercedes, Ferrari or Red Bull Powertrain: How are the engines looking?

Mercedes, Ferrari, Honda, Audi or still the new Red Bull Powertrains-Ford (RBPT) combination? Formula 1 's original equipment manufacturers (OEMs) hope their power unit will be the strongest on the grid in 2026. Meanwhile, these suppliers have entered the final stages of engine development and the excitement is mounting. Which one will be the strongest power unit of 2026?