I thought the way it works out is that : There will be no modifiers applied to TK archers, so they will use their own BS "straight out of the box". Since their BS is 2, they hit (not wound) on a 5+, if their BS is increased to 3, then they follow the shooting to-hit table, which is a 4+. If their BS is reduced to 1, they should hit on a 6+. Soft cover, hard cover, skirmishers, long range, these normal modifiers do not come into play. However, the "modifiers" from a SPELL, should have an effect on TK archers, right? If I cast Iceshard Blizzard, their archer should hit on a 6+ not 5+ right? I am assuming the TK special rule does not cover magic shooting modifiers.
The description in the Tomb Kings' rulebook says quite unambiguously that Arrows of Asaph suffer no kinds of penalties or bonuses To Hit rolls. So only if the spell changes archers' BS, it has an effect. So Iceshard Blizzard is useless (well, to be accurate, the modifier does count if you are in close combat with the archers, but at that point they usually are gone anyway. Oh, and the -1 Leadership? Umm, maybe if the army is crumbling...?). It helps against the Screaming Skull Catapult, though.
Just posted this in the tactics section, so I copied it in here, thinking it is solid enough . The original topic is here: Link to original topic The Hunted