No, completely wrong. Disconnect/connect means using shields and commerce for building units quickly. Works for all units that are upgraded from a predecessor unit that has less strategic resource dependencies. For example: Horseman (Horses) --> Knights (Horses + Iron).
- You need a warrior and 6 workers on your single iron hill. Use your warrior to pillage your iron.
- Go into all your cities currently working on your military and set them to produce Horsemen.
- Now activate your 6 workers and repair the road on the iron hill.
- Finish the turn, and whenever one of the city popups comes up announcing the completion of a Horseman, zoom into the city and upgrade the Horseman to Knight (e.g. for 80 gold, if you have Leonardo's Workshop).
- And voila: the following turn a Knight is ready to go.
- Rinse and repeat.
If you have enough cash, you can basically build Knights at the speed of Horsemen. (Or Cavalry at the speed of Horsemen, if you do the trick later on a Saltpeter resource instead of Iron.) This is much more cash-efficient than short-rushing, which would require 160 gold to "replace" 40 of the shields by commerce: e.g. in a city with 10spt, you would collect 20s in 2 turns, then switch to temple or granary (something with 60s), cash-rush it for 40x4 = 160g and switch back to Knight. In the third turn, the city production of 10spt will complete the 70s. Again you have completed a Knight in 3 turns like in the disconnect/connect example, but it costs twice as much gold.
And this is the big disadvantage of War Elephants and Ansar Warriors: they do not require iron, so the disconnect/connect strategy cannot be used on them...