Hold'em Strategy and Hand Groupings

Learn-Texas-Holdem.com
is a good place for beginners wanting to know things such as basic
holdem strategy and differences
between online and regular poker.

Of particular interest is the modified
hand groupings. Sklaskly categorizes them as:

Group 1: AA, KK, QQ, JJ, AKs
Group2: TT, AQs, AJs, KQs, AK
Group3: 99, JTs, QJs, KJs, ATs, AQ
Group4: T9s, KQ, 88, QTs, 98s, J9s, AJ, KTs
Group5: 77, 87s, Q9s, T8s, KJ, QJ, JT, 76s, 97s, Axs, 65s
Group6: 66, AT, 55, 86s, KT, QT, 54s, K9s, J8s, 75s
Group7: 44, J9, 64s, T9, 53s, 33, 98, 43s, 22, Kxs, T7s, Q8s
Group8: 87, A9, Q9, 76, 42s, 32s, 96s, 85s, J8, J7s, 65, 54, 74s, K9,
T8, 43

But Andy (the webmaster) recategorizes them as:

Group 1: AA KKQQ JJ AKs
Group 2: TT AQs AJs KQs AK
Group 3: 99 KTs QJs KJs ATs AQ
Group 4: A8s KQ 88 QTs A9s AT AJ JTs
Group 5: 77 Q9s KJ QJ JT A7s A6s A5s A4s A3s A2s J9s T9s K9s KT QT
Group 6: 66 J8s 98s T8s 55 J9 43s 75s T9 33 98 64s 22 K8s K7s K6s K5s K4s K3s K2s Q8s 44 87s 97s
Group 7: 87 53s A9 Q9 76s 42s 32s 96s 85s J8 J7s 65 54 74s K9 T8 76 65s
54s 86s

Anyone know the rational for the regrouping?