One of the things we actually don’t have a lot of knowledge regarding is the cumulative effect of wearing many different types of talismans at once.
My contention is that it is safer to use a talisman whose principal star is on the MC but those ASC is afflicted, if this is just one of several talismans whose ASC are quite strong and fortified.
This is partially why I advise the use of talismans with afflicted Ascendants for short term effects. The other reason is that it’s sometimes appropriate to use a talisman which makes the wearer unattractive, irritable, and ill temporarily if the main goal is critical.
One of the matters Picatrix and other sources disclose is that the radiation of talismans when properly made are so strong they overwrite the reality of all receptive substances in their proximity, fading gradually outward. Many of those substances — which can include people — will have nativities with afflicted Ascendants. Yet it is the very nature of talismans to overcome these faults and make them akin to the talismans.
What this means is that under most circumstances, a talisman with a strong essential dignity on a House will overcome the accidental and essential debilities of the same House of anything it encounters– even if the quantifiable number of the dignities and debilities approach zero when combined. Strength beats an equivalent amount of weakness– it does not neutralize it.
So, though I believe it’s best to have talismans without any weak ASC, there is a Traditional rationale for using a weak ASC talisman for a magus in a hurry.