Quite so.
A TAF would have to be more than substantially wrong to meet the criteria for an EIR and fall so far adrift as to make the arrival impossible, and, moreover, in that unlikely event the TAF at the designated alternate would have to fall into the same degree of error. Should that happen the EIR holder is trained and qualified to fly on instruments. Should an arrival at both the planned and the alternatives all require an approach in IMC then the pilot will call a PAN and will (should) receive all the vectoring and support required so as to avoid the complexities and "risk" associated with a procedure ending with an ILS or SAR which they should be capable of flying safely.