After some more investigating and talking to the bulbapedia maintainers of the Johto Safari Zone page I've been able to gain additional insight on the mechanics and the encounter slots of the safari zone, as such I applied what I learned and had to correct large chunks of data here.
+ Update encounter slots
+ Repositioned encounter slots IDs
+ Updated encounter conditions (Johto Safari Zone's encounter aren't affected by the presence of the national dex)
After some research I found that the Johto Safari zone uses different encounter slots for morning, day and night and I also arrived at these chances for them, I modified the encounters and added the new encounter slots as appropriate, these chances could be wrong but I experimentally tested them and believe that these chances are correct, the chances I found are as follow:
+ When walking there are 10 slots with 10% chance each
+ When fishing with an old-rod, good-rod, super-rod or when surfing the chances are as follow:
| Morning | Day | Night |
|---------|-----|-------|
| 10% | 10% | 5% |
| 10% | 10% | 10% |
| 10% | 5% | 5% |
| 10% | 10% | 10% |
| 5% | 5% | 15% |
| 10% | 10% | 15% |
| 5% | 15% | 0% |
| 10% | 15% | 0% |
| 15% | 0% | 10% |
| 15% | 0% | 10% |
| 0% | 10% | 10% |
| 0% | 10% | 10% |
Will update if more precise information becomes available
+ National Dex requirement for Hearthome Eeevee D/P
+ Defeat Jupiter Eterna City Togepi Egg
+ Remove Togepi Egg from D/P (was incorrect)
+ Clear Team Galactic Iron Island Riolu Egg
Roaming Pokémon can be encountered exclusively on grass or water in different situations in different games and at different encounter rates, which is something that wasn't reflected in the previous encounter method (which used to be only one).
+ Added Roaming grass encounter method
+ Added Roaming water encounter method
+ Moved Crystal, Firered, Leafgreen, Ruby, Sapphire and Emerald roaming Pokémon to the new encounter methods
