Well...that is a lot to address all in one post. I'll give it a spin.
Regarding extra help. Blowing is generally done last, and all the blowers I have seen that mount on a multi-tool are too ineffective to consider unless you really don't want to spend any money on a good one. So that leaves something for the latecomer to do. The best hand held blowers I have found are the Stihl BG-85 blowers. I buy those, even though I get dealer pricing on Maruyama products.
If you anticipate extra help, start the trimming first. This leaves mowing or finish the trimming for a late-comer. A skilled operator can trim in advance of mowing, and then it looks even better because the clippings from the trimmer get mulched by the mower. Some folks always trim first, although this mandates that the trimmer knows the equipment and property well enough to prevent skipped areas and return trips.
If all the trimming and mowing is done, blower can chase the edger anywhere it is needed.
Regarding quality of tools: no one makes a better hedge trimmer than Maruyama. Bar none. They are so much better than anyone else's, you just can't believe it. More durable, better starting, ease of use, safety, and most important: quality of cut.
Backpack blowers: There are quite a few ferocious backpack blowers that are quite well made that compete with the Stihl Blowers for a whole lot less money with just as much wind. I'll give Stihl big points for having about the most wind with the least noise, however.
String trimmers: I already stated my preference (Maruyama), but I won't really criticize Echo, Shindaiwa, or Husqvarna trimmers in the professional quality versions. Maruyama used to have a dealer demonstration trick where they would take a brand new trimmer, put it on the showroom floor, and challenge the buyer to jump up and down on the shaft or the handles to attempt to hurt the trimmer. That's how tough they were! Sadly, they quit making the shafts out of aircraft tubing, and they are not quite as springy as they used to be. Still, more quality than any other brand I have found.
Kawasaki is making some pretty good machines at very competitive prices also, although I have not yet purchased any. Curiously, Maruyama has built string trimmers under the other guy's label at various times in the past. I had a Husqvarna string trimmer come into my shop once for repair, and it was absolutely identical to a Maruyama ML-23s except for the color of the paint and the decals. Few people know that one of the first professional trimmers available in the 1980's (Green Machine) was made by Shindaiwa, or so I have been told. Lesco trimmers were made by Echo. There have been a lot of rebranded machines over the years.
I have met a lot of my competitors that are fond of the Stihl trimmers, but I have been mad at Stihl for many years based on my long past experience. I should probably let go of that bias, but I have never yet been mad at my current favorite. Better built, better warranty, simpler construction, and less expensive repair parts.
Regarding dealers: Husqvarna has a long history of burning out their dealers, and Echo has some tendencies to do that also. This leaves Stihl as the reigning champion among servicing dealers, although my closest dealer pretty much sucks. I only buy parts from them when I don't care if I wait a month for the part, and I always keep enough chainsaws around so that I never run out of running saws of any given saw size. That being said, I have twice as many repairs and problems with the Stihl saws as I do my XP series Husqvarnas. ...even though my favorite trimming saw is the renowned 200t. I have 4 of them!