So the common reasons for TRV refusal, I've outlined the things we're doing to address each one:
-Purpose of visit: To not only visit me and my family, but we are planning on taking a couple weekend trips together with my family, as well as visit Vancouver on one of the weekends, already provided detailed plans of the dates we are going to each event, the names of the hotels we will stay, the name of places we will go, amount of money we will spend, itinerary of me entering Vancouver to meet her to start our trip, etc.
-Travel history: Student visa to USA, lived in USA for a year, went to Singapore x2, China, Thailand, Malaysia, all within the past 5 years
-Family ties: Not much I can do because I'm the strongest tie in Canada, but having her entire family and relatives back home is about as good as a married couple can get for family ties. Don't know if this means much, but we will also indicate to them that my wife's family ties are strong because her entire family is back home, and she's lived in her family's home for her entire life, never even moved in Vietnam, so she has every reason to go back.
-Employment: Makes 5x the average Vietnamese salary, will submit all proof of employment and income received. She's doing very well financially.
-Assets + funds: Does not own property or a business, but will have over $5000 by the time we apply, which should be plenty good for just 3 weeks. Also I will have over $7000 in my account and will show that to them.
-Misc info: Will indicate in a cover letter, that I've visited my wife several times, for 2 months each time, so this time, we would like for my wife to visit me for once. Will indicate that we will purchase return tickets + insurance. Will indicate that I will take care of all expenses, transportation, etc, not a single dollar from her funds will likely be used since I'm paying for everything. She will not seek work and will leave after 3 weeks, even if granted an extension. Will show detailed plans on travelling to Europe to show she's not intending to overstay.
I dont know, I think the only downsides to her background is being married to me and she doesn't own property, but aside from that, I think her background is at least way better than most applicants from developing countries.