Do we really need anything more than 8" woofer and 1" tweeter for medium size room?

I cannot imagine (unless you have a very small room) that a pair of 8" woofers (in a speaker - not a dedicated subwoofer) will be anywhere near enough bass to really create a full range sound.  If you have a large 2-way bookshelf or even floorstander with 8" mid-woofers in them, there is no way that they will be hitting down to 25hz or lower in your room.  Even adding a dedicated powered 8" subwoofer (or a pair) will still not carry you down to the very low frequencies.  Now you may not listen to the types of music that even contain these frequencies, which is a different thing, but when you listen to some of the music that I do, there is A LOT happening down low that I never even knew was there until I bought a subwoofer like the G1.  Simple physics... if you want to reach really deep and have control at the same time, you really need a large sealed box, large woofer, and pretty decent amount of power.  And an 8" Sunfire subwoofer.... ummmm, no.

If I wanted to add subs I too would go with at least 10", but they would have to be fast enough. I keep hearing praise of JL Audio subs, and REL is well-known as a generally good choice for music.

So I listen to 12' full range drivers, open baffles, with a supertweeter. Recently added a sub for last octave re enforcement. I must say I find it amusing when people comment that 8 or 10" drivers dont do well in the midrange. Perhaps some designs dont but there are a lot of  respected opinions out there that full range drivers offer the best midrange quality rivaling planars. just my 2 cents. Fwiw, imo, theres no replacement for displacement as far as woofer size goes but 8 ' seems adequate for mid size spaces

You wanted to say 8 inches not 8 feet, I guess !

8" woofers (or subwoofers), no matter the design, are never going to dig deep enough for the types of music that I listen to and as loud as I sometimes like to listen.