A few things to consider (if I'm remebering it right)
1)Beryl and the four generals have been in the dark kingdom since the fall of the silver millenium. It has to have done some sort of workover on their minds, Insane but powerful tyrants tend to stay in power.
2)It takes power to send youma over to earth, the more youma sent a the same time the more power it takes.
3)the DD girls (I think thats the name the youma sisters use) at the end of the first series manage to kill of all of the inners but Usagi, they are neither as stupid or as powerfull as the four generals.
4)The only reason they beat Beryl is because she came to earth to summon Matillia
So it might be logical to think that if you killed of the generals long before Beryl had enough energy to summon matillia, she would have to send someone else (the DD girls come to mind) a lot sooner and as long as the senshi kill off the idiots it's going to rais the chances of Beryl actualy picking someone with enough of a brain to be a threat. The more tactics and training Doug teaches the senshi, the more experiance and better trained their opponent gets as long as the senshi don't them.
1)Beryl and the four generals have been in the dark kingdom since the fall of the silver millenium. It has to have done some sort of workover on their minds, Insane but powerful tyrants tend to stay in power.
2)It takes power to send youma over to earth, the more youma sent a the same time the more power it takes.
3)the DD girls (I think thats the name the youma sisters use) at the end of the first series manage to kill of all of the inners but Usagi, they are neither as stupid or as powerfull as the four generals.
4)The only reason they beat Beryl is because she came to earth to summon Matillia
So it might be logical to think that if you killed of the generals long before Beryl had enough energy to summon matillia, she would have to send someone else (the DD girls come to mind) a lot sooner and as long as the senshi kill off the idiots it's going to rais the chances of Beryl actualy picking someone with enough of a brain to be a threat. The more tactics and training Doug teaches the senshi, the more experiance and better trained their opponent gets as long as the senshi don't them.