Just to make a few comments. The only shady behavior here was that done by the dealer as they did not explicitly outline who they were submitting applications to in your behalf although the Ally underwriter probably could have made better choices in selecting the reasons to be listed for the denial.
There are a number of different scoring models, some of which use a standard framework (FICO 2/3/4/5/8/8 Bankcard/8 Auto/9/9 Bankcard/9 Auto,Vantage 3.0, Vantage4.0 are all well-known examples) and some of which are proprietary. Sagestream provides a proprietary score. Chase Bank as an example uses an internal proprietary model. To give 2 other examples Navy Federal and Pentagon FCUs both used proprietary models until they converted over to using FICO 9 1-2 years ago.
You can't directly compare the results from 1 scoring model to another because they look at different criteria and weight them differently. It's not uncommon to have a FICO 8 score of 800+ and a FICO2 or FICO5 score in the low 700s,and there are still a number of banks and credit unions that use FICO2 or FICO5 scores to make credit decisions. It's also not uncommon to have Vantage scores (Credit Karma, WalletHub) that vary more than 50 points from the FICO 8 score from the same credit reporting agency (Experian/Transunion/Equifax). Having a FICO 8 score of 840 and a SageStream score in the 700s is no indication whatsoever of any incompetence or dishonesty on their part but they do show you have a clean profile.
Other well-known creditors like US Bank and Ban of America also pull from Sagestream as a secondary source.
Ally is legally obligated to give you between 1-4 items from a formal list of about 80 that telling you what most influenced the decision to deny you credit. What you got may not have been the actual reason or even reflect reality in your case but may have been the best fit from those options available to choose from.
BTW a phone # with different area code than what a landline at that address would get is a risk factor for potential fraud. As is true in your case it can be a BS reason but the phone # it's accurate Ally can select it.
You should request in writing via registered mail a free copy of your Experian and Sagestream reports although with FICO 8 scores in the 840 range both you and your wife are going to have clean files.
This also speaks to why it's not a bad idea to line up financing before visiting the dealers, while for scoring purposes multiple inquiries from the same CRA will be treated as a single hard pull they are all still individually reported and current creditors will see each one of them It's not unheard of to have a dealer send out applications to 10-12 different banks/credit unions.