It wasn't til many years later did the appearance of the need for... "A model blocked from LoS that would usually block LoS doesn’t!" That line sounds confusing to those who haven't played many games but mainly why it's important.
If HQ mechanics were the same as SH, the Orc or first Chaos Warrior (Sotiris Map) would block the rest. After many plays one comes to realise, as the Orc is blocked from LoS it doesn't block LoS to what is behind it. Hence why GW FAQ the above in bold (Likely my wording not official, I forget theirs) for SH...
As for HEROQUEST, the rules clearly state the diagonal attack and LoS is allowed diagonally through the 2 blocking characters. They would be considered in the further corners of the square, leaving enough space for sight or a prod from a staff. If one was playing the SH way, the LoS to the 2nd/3rd Chaos Warriors (Sotiris Map) would be blocked.
In SH it's all about the pivot point on the corner. The rear corner of the first character you can see becomes the new pivot point, everything behind it, upto equal distance away from you, away from it, is blocked. That was a hard sentence to write, hence the diagram.
But just to be doubly clear, my stance on HEROQUEST rules is, they are allowed. Diagonal, LoS/Ranged/Magic = Not blocked. Only movement, bring on some boots of agility, purchase for the unlock. Useless if used with Heavy Armour.
