The janitor essentially functions as a one-time stalker, as he learns the victim's role upon death. There is no other way for maf to know the role of the person killed save if you stalk the kill. However, two stalkers would be horribly unbalanced.
d1 LK claims (if he died then no lights, so obvious) lynch between CCs if any. after LK claim, town RLs. n2 watcher on LK. if LK dead d2, NL because you have it. How does this sound?
So essentially you're saying to massclaim day one? The major problem with that is if maf hit a pr the night before (or the lk himself). Also, you actually DON'T want to lynch a mafia day one, even with a guilty, as the amn is less inclined to risk waiting another day to amn and might pick up the dead maf (he won't know that the cc is town or maf). The worst case scenario for maf is if they hit the amn or oracle n1.
Here are some maf tips: after n1, the stalker should be the one voting first. I've seen quite a few games where the watcher got a stalker visit but waited another night and caught the jan, too. Another thing: maf should claim mort or watcher no matter what. The exception to this is if they kill a blue n1 and the mort n2; then one should claim mort and cc the watcher claim (by saying the watcher is in the gy) and the other should claim blue.
Another potential strategy is to simply stalk the kill the whole game; that way, if the stalker is caught by the watcher, then the jan is still safe and can use his ability later.
Tell me if this idea is wrong: Mortician claims on day 1. If watcher is in the graveyard, mortician will die, and town will know exactly who is in the graveyard. If mortician does not die, we will know that watcher was not the first to die and that our mortician is clear.
Knowing who is in the graveyard is more important than having power roles for the rest of the game.