Regarding 2+2=5, I like to suggest another alternative in addition to 1+2+2=5 where 1 is the environment.
How about when we get the synergy right it's 2+2=4 and when we don't it's 2+2=3?
Let me illustrate with an anecdote. In the mid 90's I went oven to Tom Evans' house to pick up a "Digital Turntable" for a HFN piece I was doing. While I was there - fightng my way through substance-filled smoke - I listened to his system. Tom strives for linear phase throughout his system. He used Ted Jordan drivers and Michell / Trichord electronics. Trichord was Tom and Graham Fowler at that time, they both had parts to play in designing the Michell amps.
The sound of Tom's system was amazing, what I was hearing was a system approach from a single designer.
So 2+2=3, 4 or 5?
Could it be that when it's 3 we're not hearing what the designer intended due to a technical or environmental incompatibility?
When it's 4 we have synergy as the designer intended.
When it's 5 we've been drinking or smoking....
Note that I say "what the designer intended", this may not be the same as a single manufacturer such as Linn who have been known to use many different designers, often plucked straight out of uni.
TT 1 Trans-Fi Salvation with magnetic bearing + Trans-Fi Terminator T3Pro + London Reference
TT 2 Garrard 301 with NWA main bearing + Audiomods Series Six 10.5" + Ortofon 2M Mono SE
Digital Lindemann Bridge + Gustard R26 with LB external clock
Pre and Power Amp EWA M40P + M40A
Bass Amp & DSP Behringer iNuke NU3000DSP x 2
Speakers 1 Bastanis Sagarmatha Duo with twin baffleless 15" bass drivers per side
Speakers 2 MarkaudioSota Viotti Tower