It has to do with the not converted Shouts. Tutu will not convert any Shout, because it will search them in a SHOUTIDS.IDS, that comes only with TOB (I suppose, Tutu has been coded with TOB).
Charleston has a Shout in his script, if he is attacked, but he cannot Shout, because Tutu has nothing converted there. So the diggerswill not attack you.
To convert Shouts correctly you have to extend the SHOUTIDS.IDS from TOB and copy this then to BG2 _and_ BG1 Override _before_ running TUTU.
Then you have also to change the lines:
106 in the ACTION.IDS and 0x002F in the TRIGGER.IDS in both games as followed _before_ converting:
106 Shout(I:ID*SHOUTIDS)
0x002F Heard(O:Object*,I:ID*SHOUTIDS)
Here is _my_ SHOUTIDS.IDS, which containes a few own Shouts and the regular Shouts from both games (I have named them for a better overview for myself):
90
1 ATTACK1
2 LEAVE2
3 HELP3
5 HELP5
6 HELPGOND
7 HELPFLAM
8 HELPAMN
24 Help24
33 FLEETHIEVES
50 GOAWAY
57 Help57
68 SUM_ATTACK_GOOD
69 SUM_ATTACK_EVIL
79 Help79
80 HELPARCHER
81 FLEEARCHER
82 COMEARCHER
83 Help83
89 ATTACK89
99 HELPME
100 Help100
101 Help101
111 WARNALARM
115 HELP_ALIBAKKAR
116 HELP_LURRAXOL
121 Help121
122 Help122
123 HEALME
124 ASSIST
125 ALERT
126 SOLAR_STANCE
151 HELP_ME_GROUP151
152 ATTACK_MAGE
153 HELP_ME_GROUP153
154 FLEE_FROM_MAGE
155 ATTACK_MAGE
199 HELPME_DRUIDS
Shout 3,6,7,8 are my own - all others are used by the original games. Everyone can use this .IDS, if wanted.
Have Fun