Where did you see that order of battle? Everything I've seen indicates that the Plan only allowed for a single panzer division (with light tanks), plus one panzer grenadier division. Perhaps there was a muscled-up plan that I haven't seen, but any such plan would presume even more sea-lift and would therefore have been less likely.
The Royal Navy would have made a max effort against the landing beaches. A fleet does you little good if you are facing defeat on land -- ask the French. I'm sure that the RN would have run any minefield sown by the Kriegsmarine and risked the damage. Heavy fleet units would probably have sailed around Ireland & approached the landing beaches from beyond the range of Luftwaffe fighters. Running the channel would have exposed the fleet to air, mine & torpedo attack.
The order was battle was in the book, "Invasion" [an excellent read by a retired British tanker.
If the Royal Navy sails around Ireland, they ride themselves right out of the battle. The key to the Germans winning, in theory is gaining a foothold and expanding it. The more time they have, the better for them. The Brits would want to disrupt it as soon as possible.