But if that person has rare skills where at least 25% of their output makes another team of 5 100% more effective (200%), than than loss of 50% output is actually a 33% gain in output!

Say you have a team of 6 (5+1 DevOps Wizard), and a team of 5. so Call it 5x200 +5 x100% output, 1500 output total. Split our wizard in half and you get 5x200 + 5x200 = 2000 output total!

At a certain minimum level the effectiveness inverts because people are waiting on wizard magic and everyone is less effective, but there is benefit to having specialists be split.