It's an absolute nonsense to think a burglar would make himself known to an intended victim just before he burgled them.
Quite. However, one might visit say a month or two in advance, to gain some intelligence, then return when the first visit was forgotten.
My interest in this topic is actually getting a better handle on the crime pattern in Luz in the months leading up to Madeleine's disappearance. DCI Redwood seemed remarkably vague about the specifics.
It also appears to be relevant to ask how much local knowledge of Luz these collecters had. If it is the case that these people were local, and into petty crime, then they might either be involved in other local crimes, or have some knowledge of those who were.
It is the paucity of accurate information in the public domain that bothers me. We can leave this aspect to OG and hope they are better informed than we are, or we can put collective heads together to see what we come up with.
I am also interested in what possible information could have been put to the judiciary to get the 4 men of July 2014 made arguidos. There appears to be a potential link to charity collection. That OG info could be correct or incorrect, but it seems to have been strong enough to slap arguido on the quartet. I believe that particular bar is set higher than it was in Amaral's day.