Alternator and starter motor connections

[mm1000]

This might seem a very simple question but after copious amounts of research I can’t find an answer. Should the alternator have a direct connection to the starter motor (as shown in many wiring diagrams) or is just one black lead from the alternator to the battery sufficient? I have had the engine out and don’t recall disconnecting more than one black lead on the back of the alternator, assuming it wad right before!

[DRUMMOND]

1 black wire connection to starter then goes thru big wire to battery
1 black connection to fuse box L