Degrees of 'counts as' - Being reasonable?

Played two games today. One in the ongoing WHFB league i'm in and the other with the space wolf list today. Lost horribly in both cases, but i didn't mind too much. But the second game threw up issues of 'counts as' and reasonability.

Basically, we both wanted to test the new space wolves codex. Neither of us own the 'official' models, so there was a lot of 'counts as' being used.

First up, he put a Black Reach captain, a Terminator Chaplain and a Dreadnought down and said 'that's A Wolf Lord, A Rune Priest and Bjorn'. Now i'm a reasonable guy (not that i'm saying he's not), so i said, yeah, no Problem.

I then unpacked my stuff and put Sarpedon and Tellos down and said "That's Njal and a Wolf Lord". Instantly, he blurted out, pointing to Sarpedon "but he's on too big a base, you can't use him!", followed by a retort from me. I'd been using this guy for months as Tigerius (who's on a small base), with no problems, yet the moment i wanted to use him as a new character, (who is more or less the equivilant of Tigerius, but sold on a terminator base), it was apparently bang out of order, just because he had some apparently powerful special rules, which had yet to be run through the local gaming mill, so the hype over them was still believed.

However, in his new-codex-oh-my-god-it's-overpowered, he chose to ignore the fact that Tellos, my Wolf Lord, for exactly the same fluff reasons as Sarpedon, had chainblades for hands(count-as wolf claws), no chest armour (but highly mutated, so counting as runic armour and belt of russ) and no representation of the jump pack i gave him (inhuman speed). If i'd wanted to make an overpowered list, i could have classed Tellos as Canis Wolfborn, who is very Tellos-like, in that he's also fast, tough and kick-ass in combat.

It's not like i was wanting to gain an unfair advantage by using Sarpedon on a bigger base, i was merely wanting to represent one of my favourite BL characters in a fluffy manner, as well as make use of the model i'd commissioned off Ron.

If i'd really wanted to be picky, i'd have said in that case, he couldn't use his Chaplain as a Rune Priest, but instead i took the cowards way out and bargained with him. I let him use his missile launchers from his tactical squads (being thrust into the role of grey hunters) as plasma guns in exchange for him 'being reasonable' about Sarpedon. In the end, Sarpedon was vapourised by a lascannon with the opening shot of the game and those extra plasma guns cost me the match, taking out my drop pod troops as they landed. The game was over by turn three.

I wouldn't have even been bothered that much if his force hadn't consisted of a mis-match of several other SM armies, including Dark Angels and Codex Marines, with no consistancy of colouration, whereas, i'd taken the time to paint every model in Soul Drinkers colours and model things like Mark of the Wulfen clearly (mutations). The only reason why Sarpedon isn't on a terminator base is because when building him, Ron suggested that he'd look better on a bigger base, else he'd look ridiculously squashed in on a 40mm one.

Speaking to Colin, the club organiser afterwards, he said it was a little unfair considering it was a friendly game and if he was in that position he would have let me use Sarpedon without forcing concessions upon me. But unfortunately there is a fair sprinkling of competitve players in my local gaming group, whereas me and Colin are more in favour of balanced or fluffy lists, so there's often clahes of 'gaming personalities'

So, who would you favour in this situation. Me or him?

How far should people reasonably take 'counts as'?