Attribution is a negotiation, not a measurement
Stop searching for the true attribution model. Agree one with sales, write down its assumptions, and use it consistently.
There is no attribution model that tells you what caused a deal. There are only models that distribute credit according to rules you chose. Once that is accepted, attribution becomes a much calmer conversation.
Pick rules you can explain
First touch, last touch, a simple position-based split. Anything a sales leader can understand in one sentence. The multi-touch models sold by vendors are not wrong, but their opacity makes them useless in a budget argument.
Agree it with sales
Marketing attribution that sales did not sign off on is a report nobody reads. Sit down, agree the definitions of sourced and influenced, and put them in a shared document with a date on it.
Change it rarely, and loudly
The value of an attribution model is consistency over time. If you change it, restate the last four quarters under the new rules and say so in the board deck.
Triangulate
Run two or three other checks alongside: self-reported source on the form, a quarterly lost-deal review and a holdout region for paid campaigns. Where they disagree with the model, that is where to look.
