Using multiple forms of myco's and fungi is never considered "overkill" in my book. Neither feed off each other so, yeah it's ok to use at the same time.
MOST quality organic soils already contain "living"(dormant) colonies of both. Once the plant is potted in these soils. The colonies become active and grow through out or grow onto it's new home. The use of added bio's is not needed, but I still add some back every time I use an AACT tea as they come from the worm castings and alfalfa/kelp (kelp also adds natural Humic and Fulvic acids) meal naturally.
I have soil-less and soil friends that dip their roots directly into the great white right out of the cloner. I have others that simply mix it into their water, even during cloning. Soil and soil-less grows do not need additional treatments other then your first, but if you use synthetic nutrition you should periodically re-add some. It is a WIDELY believed MYTH that synthetics "kill" myco's etc. That is NOT true! What synthetics DO is to put some into dormant states from high P concentrations and from other interactions. The regular use of Kelp products help this by adding the "good" Humic and Fulvic acids that help reduce nutrient build-up's (In a sense or in a way, as they increase nutrient uptake/regulate P).
The use of silica, helps regulate P. P can be the single biggest problem in growing our chosen plant. They will use what it needs and actually stores some in the plant for later use in flower (for the start of). The over use of P will cause yellowing of the leaves from the bottom up and out the branching to even into the bud leaves. I see this as one of the most encountered problems on this site. The use of added "P" in flower should be done carefully!
Note: There are many Humic acid supplements available. I find that many are not as effective as they could be (from what they derive it from to how concentrated they are [or aren't to be accurate]). The single most effective Humic and Fulvic acid supplement I have found is SEA GREEN. When used, I have to reduce my nutrient application by 50% or burn the plants!!
I hate to spread corporate propaganda. But, with that said. I will share this That I first saw in a Hydro Life mag a few years back. Re found it online in a PDF.
This has some very good info on living soil bio's/myco's
http://www.plant-success.com/images/stories/super_feeding_article_web.pdf
I noticed you mentioned the use of a bio as a foliar. I use a basic AACT tea as one also from time to time if I need. It keeps problems with molds and fungus's at bay. You simply take out a cup at 18 hrs of brew time and apply and let the rest go it's normal amount for the Bio tea.
Keep growing