I never played the Amiga version, so I don't know what the bugs are there. It certainly seems like a bug though, Boldin not joining. I have played the PC version extensively though, so there's a couple of bugs here that you can take advantage of if you want an upper hand on the game. Of course you can choose to simply not use them if you're a gaming 'purist'
Two of the main bugs worth mentioning are the 'Item Charge' bug, and the 'Missile Bug' as I call them. The Item Charge bug occurs when you use up all the charges in a magic item, and while the item will disappear from your inventory (make sure it's equipped before you use the last charge), all the attributes the item gave will stay with your character. For example, with the Firebasher and Frostbiter swords that you can find, give them to one of your fighters and use up the charges on both, one after another. Your fighter will now have like 40+ damage, AND an empty slot in hand to place another weapon. Not to mention that the character also retains special bonuses as well such as +LP, +SP, or +Attributes. This can be used for any equippable items such as swords, staves, helmets, brooches, armor, basically anything that has magic charges that can be used up. Think it's not fair? Well there's another bug which dis-allows you to use the "balsam" potion, which gives like +60 damage for 10 rounds to your character (the game crashes when you drink it) so I think it all evens out
One thing to watch out for though is a "counter-bug" which occurs if you do this too many times on other characters. You will notice that every time you exhaust a weapons charges, your main character's weapon or armor value(depending on whether it was weapon or armor that you were exhausting of charges) will be MINUSED by however much armor or damage you have from your weapon. Wait, I know this sounds confusing, but let me make it simpler. Say you have two characters. You give Firebasher to your second character and you use all the charges in order to take advantage of the bug. Your first character is holding a knife (nothing else) which has 3 damage. When you use up the last charge on the Firebasher, you will notice that your first character now has 0 attack. If you unequip the knife, the attack will go down to -3. It's the same with armor. There is however a way to get around this. Try to get the Bi-Handed sword from Sansri's Temple, and the Boots or Clothes of Moira from wherever. As you may know, both are cursed items (Bi-handed sword does -5 damage, and armor of Moira gives 0 armor), but I'm sure you can already guess how they may be used to cheat this bug. Just equip them on your main character, then exhaust the charges on your weapon or armor. You'll have to pay a healer to destroy them for you afterwards though.
The second bug, the 'Missile Bug', occurs when you hold a missile weapon (Bow, Longbow, Sling) in your hand, and instead of holding an arrow in your right, hold a SHIELD (Towershield, Shield of Parry, Buckler). Next time you attack, your character will fire the shield as if it were an arrow, and the shield's defense/attack and anything else you gain while holding it will be added to your character! But the shield will disappear, which means you are free to put another shield in and watch your defense count soar! Be warned though that having multiple shields of the same type in your inventory as the kind you are firing, they will all disappear. Best to use a combination of roundshields, bucklers, small towershields, and towershields. You can stack as many shields as you want on your character, and unlike the other bug, this one has no negative side effects. So when you find that chest in the Castle of Manyeyes with like 20 shields in it, don't sell them
... You know what to do.
I'm not sure if these bugs are present in the Amiga or German versions, so you should test them out if they work.