As for the Arrow, again, no.

Before the Arrow, DeHavilland Canada designed the Jetliner.  But not even TCA (i.e., now Air Canada) would buy it, dooming the project commercially.

DHC succeeded on the basis of a series of successful, large production run designs - the Chipmunk, Beaver, Otter and Twin Otter.

The Cariboo and the Buffalo were paid for by the US Army, and when that funding ran out, the company nearly went belly-up.  Like the Buffalo, the DHC-7 was a phenomenal specialist aircraft, but was not a commercial success.  The DHC-8, however, has been an outstanding design, and great commercial success - after the government swallowed its development cost to get Boeing to bail it out, and after Boeing then lost $1 million/day when it owned DHC from 1986 - 1990.  Bombardier picked up a successful design for a song in 1990.

None of this had anything to do with the Arrow.