Goetic Summoning and Theurgy

Now I've read some of the older discussions regarding theurgic daemon summoning and attempting the same trick with goetic summoning. That seems to be something that people think is possible, if handled with care.

There is another theurgic spirit trick that raises interesting questions about the spirits that are out there to summon and whether a Goetist would be able to somehow do the same.

Spell Spirits.

The theurgic spells 'Invoke the spirit of X' basically stipulate that there are numerous/ubiquitous spirits in mythic europe that can evoke magic-like effects. Like summoning a lightning spirit that usually likes to play in storms, and having it throw some lightning. A simple example, but you get the picture.

These are feats of theurgic magic that, in the theurgy writeup at least, require the investment of a season to do the 'spell research' which is described more as spending the time to find the right spirit, learn it's name, and establish a working relationship with it ( after the first casting etc. ).

What is to prevent a goetic summoner from finding one of these spirits via scouring or in a grimoire and investing a similar season of time into learning their true name to be able to summon them?

Right now I'm thinking a season spent for a spirit plus modifiers of up to half of their summoning total, or within their 'easy to control' range doesn't sound too unreasonable if I was gming. With most goetists totals that would limit them usually to fairly low might spirits and penetration... but it would open up an interesting new range of true names to study, and effects to call upon from their spiritual retinue.

Side note:
Don't have the books at hand, but I just realized that your hermetic focus in spirits might not apply to the supernatural abilities of summoning and all. This is no great deal, as you could do almost the same things with regular hermetic spells.

Issues of wording aside, given that the goetia writeup allows you to replace it's usual total with your Rego Vim total I don't think it is much of a stretch to call that a casting total and have the virtue apply as normal to a traditional Technique+Form combination like that.

Especially when it is an ability that falls squarely and completely within the spectrum of the focus.