The Enviro 500s were ordered to go on the 62 road so Parkhead was to get all of them along with all incoming Tridents that year. The story was the Baillieston loop wouldn’t accommodate the E500s, yet same length single deck B7RLEs managed. The other story was that Parkhead had no adblue, but this wouldn’t have been an issue as AdBlue tanks did end up there in 2012 and were put next to the diesel fuel pumps so that wouldn’t have been a problem, so who knows? Larkfield got these E500s without any thought and they really could only be used on the 5, 44 and 75 and it stayed that way.
As for Tridents, Parkhead definitely lost new buses for these and the breakdown rates increased big time. Unlike Larkfield, who only had Tridents out daytime Mon to Sat only, Parkhead had them out on core routes the full day which was no use. The 51 and 53 plate Tridents saw off a lot of the older Presidents and were refurbished (some to a high standard with normal layout, others not so good) but these arrived in good condition.
Apart from Dumbarton & Overtown all depots had their share of Tridents.