Frogs are only mixed with a deck if the deck has access to tribute monsters, because frog engines generate tribute fodder better than most decks. X sabers have no need for tribute fodder, therefore making them unlikely to be better than when they were separate - Either frog lancer/monarch or x saber. Not both. As for nordics, they too have no need for a tribute fodder engine such as frogs.
You cant mix any archtype with another, they need something to stick them together. Eg. Frogs - create tribute fodder, monarchs - need tribute fodder. Therefore they fit together and can be mixed.
Also tirion, i see what youre saying, (After all, I have played frogs for 3+ yrs, hence the name FrogSage) but with the amount of cards that should be taken out would basically mean 'a new deck', even if he wants to play BW, then just bora, pot of duality, and mirror force (sorry if i missed anything else) should be kept, that means he will have to trade/buy the other 37 cards to finish it and make it as good as can be. So he may as well trade/buy something competitive.
Dax and I simply offered suggestions to which are 'good', alternate decks to play. After all, Why buy/trade for a 'dead' deck when one could play a top tier deck? Also another point, (for herman) I too enjoy funny, unexpected, decks made from weird themes put together, but only will I pay/trade for something if I know I can make a profit or that the deck has potential. (Eg, I played Plant Zombie for Regionals. Couple months later, Plant Zombie topped a YCS. Same with frog, i bought them. Later they won worlds) So back to the point, you should only pay/trade for something you feel is good and has proven so. If you believe blackwing is still good, by all means go for it. (I however, dont think blackwing is good anymore). After all, all top tier decks start with one person (or many) who saw potential and tried it.