就1 scales time: the action lands right behind the first event. 就2 scales amount: a small scope already reaches a high count. Same char, different axis.
連…都… includes the hardest single case so the rest follow; 就2 totals a high count off a narrow scope, stressing the number, not inclusion.
這個路口就四家。 (no scope-marker, reads as bare promptness/only) → 光這個路口就有四家。 (just this intersection already gives four)
光這個路口有四家就。 → 光這個路口就有四家。 (就 sits before the verb, never trails the count)
光這個路口才有四家。 (才 = only four, fewer than hoped) → 光這個路口就有四家。 (就 = four already, more than expected)
English carries this with 'alone' or 'already' attached to the scope ("this corner alone has four"); 就 is fixed before the verb of quantity, not next to the noun, and never opens the clause.