You're making this all about Harry and assuming that Alfred is passive once Harry starts the action. Lara and Feydis may be weaker, but their reaction speed is better than any warden's and they were sunk without a chance to dodge. Harry can have Alfred bury them repeatedly as soon as they pop up. And all Harry has to do is break LOS from his attackers. He knows their exact locations and they'd have to search for him in a forest of actively hostile terrain, trees swatting them with bone crushing force and every animal trying to gnaw their faces off. It's far more likely that Harry gets the drop on them rather than vice versa. And that's the least Alfred can do, we don;t know what the bigger defenses actually are.
Alfred has always been somewhat passive when he is not under order. Remember him letting the fae pound on him? He didn't run Harry off. Yes, Lara and Freydis are faster. And they never got Harry into range of their attacks - they were all hand to hand. So Harry had time. If Harry faced off with the Wardens and SC, he is in range at all times. He zaps Eb and LtW, Mai zaps HIM. He has to take 7 out before they can fire.
Break LOS? First, he has to do it. You think that the Blackstaff never had to find an invisible target and deal with that? Body heat. heatbeat. Echolocation. If Joe shapeshifts to a bird - he is not ON the island, he is ABOVE it. All 8 have effective attacks, Lara and Freydis had NONE until they could close. Alfred seems to be one at a time. Why didn't he scoop up Corb and a couple of others when he got Ethniu? Because he does one thing at a time. Yes, harry could fort up, go down into the cell block before the SC arrives, lock the door behind him, and tell Alfred to chase anyone who comes on the island away, and then let harry out. But that is not the same as fighting 3 Senior Council and 4 Wardens likely more on Morgan's level than, say, Carlos.
I think harry could hole up, and set a perimeter and be very hard to root out on the ground, and impossible in the jail, but once they get on the island? haven't seen an ability to take out a lot of targets. Powerful ones, yes, even Mab, but in small numbers.