I made the same choice. I have to cut slopes and high stump for removal often, and needed a capable and lightweight saw to run a 28” bar. I realized beforehand that by the time I got the 400 and spent money on it to make it suitable ( 3/4 wrap, dogs, larger clutch cover, oiler etc) I easily could have had a 462…. But I wanted to make the 400 work. And it does. Now it gets used for the work described above, as well as pretty much everything else. I climb with it, limb and brush, whatever needed. It’s a great saw and at no point have I thought man I should have just got a 462.It's a sliding scale, for another bump in price and a small weight penalty over the 462, you can get a 500i.
For the average person who is cross-shopping the 400/462 and are only on a 2 or 3 saw plan, the 462 is the clear winner IMO. It's probably the correct choice for the OP...but the 400 does have a place in the line up.
For me on my almost 10 saw plan, it didn't make the most sense. I already had 5 saws over 70cc and my next smallest saw was 50cc, so a 60ish cc sized saw seemed to be the glaring hole. I've got quite a bit of time running a wrap-handled 362cm(work saw, not mine) so something that handled like the 362 but with better power, seemed like the ticket. The 400 walks all over the 362 as far as power goes.
The 400 has become my "all around" saw. I use it for spar work on removals, I fall with it, I limb, and even cut brush...very versatile saw.
I understand why others question your rationale, but I get it. It was my thinking also.