i mean if you want to play cbn all you have to do is stick to the good ol
judges magicians assyrians and play shipwreck.. i mean arguably it's still the most consistent deck in terms of power/speed.. basically took 2nd at nats this year. so keep in mind if you do play a coliseum deck, play a fast deck to keep ahead of your opponent because you may only wind up with a few rescues/blocks using it if they are playing shipwreck- especially when your opponent is playing judges assyrians throne and is drawing 16 cards every turn and has multiple ways to take it out.
i still 5 0 with an old build i played at state/regionals against new decks.
obviously it boils down to the player/card selection/draw, but i will tell you i have gone undefeated with several different kinds of decks only to lose to judges magicians assyrians - it is also pretty dominant in the t2 category and here's why
2/2 assyrian survivor 12/12 asa with cbn topple anything + all the good enhancements including confusion with interrupts and solid negates, and banding + access to the serpent who is arguably the best ec in the game so you can block high or low when necessary
2/2 jair 2/2 gideon all with drawing and auto draw/search and angel with a secret name making judges cards cbn - generally getting initiative and able to play potentially cbn enh when your opponent probably only has 2 evil negates tops
so all this said, play coliseum or not? well coliseum is conceptually my favorite card since it balances long lasting problems
if you want to build a coliseum deck using non cbn enhancements i suggest throwing in other problem forts and playing it with a theme such as evil kings of judah or babylonians with hq. this will give you coliseum, a myriad of brown cbn enh you can play through it, initiative ecs like king zedekiah and king abijam to take out low cutters, and king rehoboam who can do all kinds of nasty with your offense.
generally speaking i have found the shipwreck for coliseum does work to ensure you can play cbn enhancements, but if your opponent isn't playing any forts or sites, you wind up with a dead dom slot.. something like broken covenant can make up for this if you do choose to play cbn enh so you have something to pitch for a draw or dc cov
basically, to answer your question, if you plan on not playing cbn enh and your offense isn't hurt by coliseum- play it. there are a lot of times when coliseum is very helpful
disciples is another offense to be mindful of because a thaddeus for 8+ can be devastating and disciples are also potentially very fast.
since the printing of coliseum i have seen fewer chump blocks played. i think hypocrisy has become the best evil enhancement in the game, only rising above scattered because of coliseum and you will remain.
hope this info helps!