To answer the OP, I also advise you to give him Second Edition.
All the new cards in Second Edition Base have conditions or decisions, whereas Spy was the only decision-heavy card to be removed.
To be clear: I do like the new cards. They just don't feel right for new players, or for Base.
I think that comparison is pretty unfair. For instance, Bandit is less decision-heavy than Thief, and the decisions (when there are any) are spread out among the other players rather than all made by you. Merchant has a "condition" but man come on. It's not complex.
Artisan is a very decision-heavy card, I'll give you that. Sentry could be simpler, as discussed. The rest of the new cards have a smaller decision space than Workshop. Is Workshop too complex for the base set?
EDIT: Or to put it another way, Feast is a more decision-heavy card than Merchant, Vassal, Poacher, and Bandit. Also Harbinger misses a lot, so there's not always a decision there.