What you describe is indeed what we do when we conduct a "market simulation" with conjoint part-worths. You add the part-worths for one level from each attribute to construct the total utility for each product alternative.
But...
If the attributes in your experiment that include levels corresponding to options 1, 2, or 3 represent all the attributes that in the real world describe options 1, 2, and 3, then this makes sense.
However, if not all the information that makes up the differences among the options is included in your attribute list, then you will be missing important information that would be needed to predict which option each respondent preferred.