After playing with and aggainst this deck hundreds of times, I know how to build it almost by heart.
Great. I don't think alehaak asked for an 'expert' to come and tell him exactly what was wrong with his deck. 
First, drop 1x
tower walkway and add 1x
Troop tower.
Troop tower is the key card to this deck, you need four cause you can't be afraid to discard it to take control of a site. The sooner you control the first site, the sooner you start stacking your guys and then the fun starts. Remember, with besiegers it doesn't matter that much how many sites you control, but how many stacked guys you have, cause that will give you strength bonus and will help you drop your ologs. They HAVE to come free and all at once. If someone tells you not to play 4x Ologs it's because this someone never played besiegers and have no idea what they're talking about

@NB: Olog too pricey? LMAO congrats NB, another very useful post

u clearly have no idea what a besieger deck is like and yet ur trying to teach someone!
NBarden may not know exactly how to build your 'wonder-deck' but that doesn't mean he has no idea what a besieger deck is like. There actually are other types besieger decks out there. Isn't that amazing? 
@King98: Not enough minions? LMAO this is not Moria not Forest Nazguls, sorry... we can all count minions, so if you can't add something else, just leave it
Who put you in charge? NBarden and King98 are actually helping alehaak better than you are, they're giving
suggestions relevant to the deck type instead of arrogantly telling him how to build a 'correct' deck. 
Drop all
Great Siege-towers,
Some Secret Art of Flame and
Their Marching Companies... just slow and unefficient in this deck, forget them. Forget about the berserker too, and forget about threats... it's not what besiegers are all about, unless you want to do your own version of besiegers, but seems like urs is not working and you want one that works
Possibly the most arrogant paragraph yet! Once again ordering him to 'forget about threats', I've played besieger threats before and while they don't drop a huge bomb they work just fine. Who are you to say, 'threats are not what besiegers are all about'? The next sentence is even worse: 'unless you want to do your own version of besiegers, but seems like urs is not working and you want one that works'. Of course he wants to do his own version! And who are you to say that it doesn't seem like it 'works'? You probably haven't even play-tested his deck yet. 
This deck focus on (in this order):
.controlling sites
.stacking guys
.playing,
ALL AT ONCE, 4x ologs
for free + keepers stacked + minions in your hand + minions you play after olog wins
For controlling sites:
1x
Tower Walkway4x
Troop Tower4x
Siege Troop4x
Din of ArmsFor stacking guys:
3x
Gorgoroth Keeper - perfect, stacks and plays later on the swarm
3x
Gorgoroth Breaker - Seems odd at first, but you'll always stack him and it means +1 for all your guys for each breaker stacked.
2x
Gorgoroth Troop - Stacks plus helps eventual overwhelming. Use him to stack keepers if u see they won't survive until regroup. Pretty much stack everything u can, actually

2x
Gorgoroth Pillager - This was my latest addition since it raised deck size to 37... this is how my brother plays and the pillager stacked makes a #$&*@! of a difference... anyway, if you wanna keep under 35, I think he's the one that should be cut.
4x
Gorgoroth Assassin - multi functional

usually just assign him to anybody, makes sure he survives, discard him and
troop tower to take a site, that's how he works... later, use him on the swarm to fight the big guy and let the ologs free. I have had my
Cirdan fight him inumerous times while other ologs were eating my companions alive

And finally...
4x
Olog-hai of mordor - The star of the deck

2x
Encirclement2x
Ithil Stone2x
Grond, Hammer of the UnderworldGreat. I don't think anyone asked for your deck list, Mr. Know-it-all. Go tell someone who cares, and take your unfathomable arrogance with you. 
To a total of 35 or 37 cards. I think this is the correct way to play besiegers. This deck IS slow, you need a fellowship good enough to hold until you have the bomb, but the bomb is so huge, it's ridiculous: you'll be playing 4 ologs for free, plus all keepers stacked plus all minions in your hand, and as ologs win, you play more besiegers... with 4 stacked minions and 3 sites controlled, all your besiegers are +7 and fierce if pillager is stacked.
There is no 'correct' way to play besiegers. There are many good ways. You may know how to build a good besieger bomb deck but that doesn't qualify you as an expert on all deck types using besiegers. When someone posts a deck they are usually looking for ideas to make the deck better, not re-write it completely. Go start your own besieger deck topic instead of completely rebuilding alehaak's deck for him.Did I say I love them?

Yes you did. You never mentioned how much you love to be condescending to 'decks that don't work' however.